//*******************************************
//DO NOT REMOVE THIS COPYWRITE INFO!
//Mortgage Qualification Calculator V1
//1998 Daniel C. Peterson ALL RIGHTS RESERVED
//Created: 08/21/1998
//Last Modified: 07/15/2009
//This script may not be copied, edited, distributed or reproduced
//without express written permission from
//Daniel C. Peterson of Web Winder Website Services
//For commercial use rates, contact:
//Dan Peterson:
//Web Winder Website Services
//P.O. Box 11
//Bemidji, MN  56619
//dan@webwinder.com
//http://www.webwinder.com
//Commercial User Licence #:5754-1409-60-1195
//Commercial Licence Date:2010-05-03
//*******************************************



function computeMonthlyPayment(prin, numPmts, intRate) {

var pmtAmt = 0;

if(intRate == 0) {
   pmtAmt = prin / numPmts;
} else {
   
   if (intRate >= 1.0) {
     intRate = intRate / 100.0;
   }
   intRate /= 12;

   var pow = 1;
   for (var j = 0; j < numPmts; j++)
      pow = pow * (1 + intRate);

   pmtAmt = (prin * pow * intRate) / (pow - 1);

}

return pmtAmt;

}




function sn(num) {

   num=num.toString();


   var len = num.length;
   var rnum = "";
   var test = "";
   var j = 0;

   var b = num.substring(0,1);
   if(b == "-") {
      rnum = "-";
   }

   for(i = 0; i <= len; i++) {

      b = num.substring(i,i+1);

      if(b == "0" || b == "1" || b == "2" || b == "3" || b == "4" || b == "5" || b == "6" || b == "7" || b == "8" || b == "9" || b == ".") {
         rnum = rnum + "" + b;

      }

   }

   if(rnum == "" || rnum == "-") {
      rnum = 0;
   }

   rnum = Number(rnum);

   return rnum;

}



function fns(num, places, comma, type, show) {

    var sym_1 = "$";
    var sym_2 = ""; 

    var isNeg=0;

    if(num < 0) {
       num=num*-1;
       isNeg=1;
    }

    var myDecFact = 1;
    var myPlaces = 0;
    var myZeros = "";
    while(myPlaces < places) {
       myDecFact = myDecFact * 10;
       myPlaces = Number(myPlaces) + Number(1);
       myZeros = myZeros + "0";
    }
    
	onum=Math.round(num*myDecFact)/myDecFact;
		
	integer=Math.floor(onum);

	if (Math.ceil(onum) == integer) {
		decimal=myZeros;
	} else{
		decimal=Math.round((onum-integer)* myDecFact)
	}
	decimal=decimal.toString();
	if (decimal.length<places) {
        fillZeroes = places - decimal.length;
	   for (z=0;z<fillZeroes;z++) {
        decimal="0"+decimal;
        }
     }

   if(places > 0) {
      decimal = "." + decimal;
   }

   if(comma == 1) {
	integer=integer.toString();
	var tmpnum="";
	var tmpinteger="";
	var y=0;

	for (x=integer.length;x>0;x--) {
		tmpnum=tmpnum+integer.charAt(x-1);
		y=y+1;
		if (y==3 & x>1) {
			tmpnum=tmpnum+",";
			y=0;
		}
	}

	for (x=tmpnum.length;x>0;x--) {
		tmpinteger=tmpinteger+tmpnum.charAt(x-1);
	}


	finNum=tmpinteger+""+decimal;
   } else {
      finNum=integer+""+decimal;
   }

    if(isNeg == 1) {
       if(type == 1 && show == 1) {
          finNum = "-" + sym_1 + "" + finNum + "" + sym_2;
       } else {
          finNum = "-" + finNum;
       }
    } else {
       if(show == 1) {
          if(type == 1) {
             finNum = sym_1 + "" + finNum + "" + sym_2;
          } else
          if(type == 2) {
             finNum = finNum + "%";
          }

       }

    }

	return finNum;
}


function computeForm(form) {

   var alert_txt = "";

   //**************SET RATIOS HERE*****************
   var house_pmt_to_income = .33;
   var debt_to_income = .41;
   //**************END SET RATIOS*****************

   //IF REQUIRED FIELDS EMPTY, ALERT AND KILL SCRIPT
   if(document.calc.grossPay.value == "" || document.calc.grossPay.value == 0) {
      alert("Please enter your gross annual income.");
      document.calc.grossPay.focus();
   } else
   if(document.calc.downPay.value == "" || document.calc.downPay.value == 0) {
      alert_txt = "Please enter the amount you have available for the down payment. ";
      alert_txt += "You will likely need at least 5 percent of the purchase price ";
      alert_txt += "in order to qualify for the mortgage.";
      alert(alert_txt);
      document.calc.downPay.focus();
   } else
   if(document.calc.intRate.value == "" || document.calc.intRate.value == 0) {
      alert("Please enter the annual interest rate you expect to pay.");
      document.calc.intRate.focus();
   } else {
   //START REQUIRED FIELD VARIFICATION

      //SET OPTIONAL BLANK FIELDS EQUAL TO ZERO;
      var VmonthlyDebtPmts = sn(document.calc.moDebts.value);
      if(VmonthlyDebtPmts == 0) {
         VmonthlyDebtPmts = 0;
      } else {
         VmonthlyDebtPmts = VmonthlyDebtPmts;
      }

      var VmoInsurance = sn(document.calc.moInsurance.value);
      if(VmoInsurance == 0) {
         VmoInsurance = 0;
      } else {
         VmoInsurance = VmoInsurance;
      }

      var VmoPropTax = sn(document.calc.moPropTax.value);
      if(VmoPropTax == 0) {
         VmoPropTax = 0;
      } else {
         VmoPropTax = VmoPropTax;
      }


      //COMPUTE MONTHLY INCOME BASED ON ANNUAL INCOME
      var VgrossPay = sn(document.calc.grossPay.value);
      var monthlyIncome = VgrossPay /12;

      //MORTGAGE PAYMENT CAN'T EXCEED 28% OF MONTHLY INCOME
      var maxIncomePmt = monthlyIncome * house_pmt_to_income;

      //MORTGAGE PAYMENT PLUS DEBT PMTS CAN'T EXCEED 36% OF MONTHLY INCOME
      var maxDebtToIncomePmt = debt_to_income * monthlyIncome - Number(VmonthlyDebtPmts);

      //USE THE LOWER OF house_pmt_to_income% OR debt_to_income% AS MAXIMUM HOUSE PAYMENT
      var maxHousePmt = 0;
      if(maxIncomePmt > maxDebtToIncomePmt) {
         maxHousePmt = maxDebtToIncomePmt;
      } else {
         maxHousePmt = maxIncomePmt;
      }

      //IF MAX HOUSE PAYMENT IS LESS THAN $1, ALERT & KILL SCRIPT
      if(maxHousePmt < 1) {
         document.calc.downPay2.value = "";
         document.calc.loanAmt.value = "";
         document.calc.homePrice.value = "";
         document.calc.moPay.value = "";
         alert_txt = "Based on industry standards you would not qualify for a home mortgage. ";
         alert_txt += "In order to qualify you will need to either increase your annual ";
         alert_txt += "income or lower your monthly debt payments, or a combination of both.";
         alert(alert_txt);
      } else {
         //START HOUSE PAYMENT VERIFICATION

         //ADJUST HOUSE PAYMENT DOWN TO REFLECT MONTHLY INSURANCE & TAX
         maxHousePmt = Number(maxHousePmt) - (Number(VmoInsurance) + Number(VmoPropTax));

         //COMPUTE MAXIMUM HOME PRICE BASED ON DOWN PAYMENT
         var VdownPmt = sn(document.calc.downPay.value);
         var maxDownPayPrice = VdownPmt / .07;

         //COMPUTE MAXIMUM LOAN AMOUNT BASED ON DOWN PAYMENT
         var maxDownPayLoan = maxDownPayPrice * .93;
         var maxLoan = maxDownPayLoan;

         //GATHER VARIABLES FOR PAYMENT AND PRINCIPLE COMPUTATIONS
         var VintRate = sn(document.calc.intRate.value);
         if(VintRate >= 1) {
            VintRate = VintRate / 100;
         } else {
            VintRate = VintRate;
         }

         VintRate = VintRate / 12;


         var Vterm = 0;
         if(document.calc.term.selectedIndex == 0) {
            Vterm = 180;
         } else
         if(document.calc.term.selectedIndex == 1) {
            Vterm = 240;
         } else {
            Vterm = 360;
         }

         //COMPUTE PRINCIPAL PAID ON MAXIMUM MONTHLY PAYMENT
         var prin = Number(maxHousePmt) - (Number(maxHousePmt * VintRate));
         var intPort = 0;
         var prinPort =0;
         var count = 1;

         while(count < Vterm) {
            intPort = prin * VintRate;
            prinPort = Number(maxHousePmt) - Number(intPort);
            prin = Number(prin) + Number(prinPort);
            count = count + 1;
            if(count > 360) {break; } else {continue; }
         }

         var maxPmtLoanAmt = prin;

         //COMPUTE MONTHLY PAYMENT BASED ON MAXIMUM LOAN AMOUNT

         var factor = 1;

         for (var j = 0; j < Vterm; j++) {

            factor = factor * (Number(1) + Number(VintRate));
         }


         var maxLoanPmt = (maxLoan * factor * VintRate) / (Number(factor) - Number(1));

         //CHOOSE THE LESSOR OF THE TWO PAYMENT AMOUNTS
         var maxMoPmt = 0;
         if(maxHousePmt > maxLoanPmt) {
            maxMoPmt = maxLoanPmt;
         } else {
            maxMoPmt = maxHousePmt;
         }

         //CALCULATE FINAL TOTALS BASED ON FINAL MAX MONTHLY PAYMENT
         var prin2 = Number(maxMoPmt) - (Number(maxMoPmt * VintRate));
         var intPort2 = 0;
         var prinPort2 =0;
         var count2 = 1;

         while(count2 < Vterm) {
            intPort2 = prin2 * VintRate;
            prinPort2 = Number(maxMoPmt) - Number(intPort2);
            prin2 = Number(prin2) + Number(prinPort2);
            count2 = count2 + 1;
            if(count2 > 360) {break; } else {continue; }
         }

         var finalMaxLoanAmt = prin2;

         //CALCULATE CLOSING COSTS
         var closeCost = finalMaxLoanAmt * .02;
         var finalDownPay = VdownPmt - closeCost;

         //ENTER TOTALS
         document.calc.downPay2.value = fns(finalDownPay,2,1,1,1);
         document.calc.loanAmt.value = fns(finalMaxLoanAmt,2,1,1,1);
         document.calc.homePrice.value = fns(Number(finalDownPay) + Number(finalMaxLoanAmt),2,1,1,1);
         var finalMoPay = computeMonthlyPayment(finalMaxLoanAmt, Vterm, VintRate * 12 * 100)
         //document.calc.moPay.value = "fns(maxMoPmt,2,1,1,1);
         document.calc.moPay.value = fns(finalMoPay,2,1,1,1);

         var help_txt = "";

         //DISPLAY SUMMARY
         help_txt = "After testing your entries against mortgage industry standards the ";
         help_txt += "highest priced house you could qualify for is " + document.calc.homePrice.value + ".  ";
         help_txt += "Obviously this amount is merely an estimate.  The actual ";
         help_txt += "amount will vary from lender to lender. ";
         help_txt += "Click in any result field ";
         help_txt += "to see an explanation of each result.";

         var v_summary_cell = document.getElementById("summary");
         v_summary_cell.innerHTML = "<font face='arial'><small><strong>Summary:</strong> " + help_txt + "</small></font>";

         var help_cell_1 = document.getElementById("help_1");
         help_cell_1.innerHTML = "";


      //END HOUSE PAYMENT VERIFICATION
      }

   //END REQUIRED FIELD VARIFICATION
   }

}

function help(help_id,txt) {

   var help_cell = document.getElementById("help_" + help_id + "");
   help_cell.innerHTML = "<font face='arial'><small>" + txt + "</small></font>";

   for(var i = 1; i<3; i++) {

      if(i != help_id) {

         var clear_cell = document.getElementById("help_" + i + "");
         clear_cell.innerHTML = "";
      }
   }

}


function clear_results(form) {

   var v_summary_cell = document.getElementById("summary");
   v_summary_cell.innerHTML = "";

   document.calc.downPay2.value = "";
   document.calc.loanAmt.value = "";
   document.calc.homePrice.value = "";
   document.calc.moPay.value = "";

}

function reset_calc(form) {

   var v_summary_cell = document.getElementById("summary");
   v_summary_cell.innerHTML = "";

   var help_cell_1 = document.getElementById("help_1");
   help_cell_1.innerHTML = "";

   var help_cell_2 = document.getElementById("help_2");
   help_cell_2.innerHTML = "";

   document.calc.reset();

}