browserName = navigator.appName;
	browserVer = parseInt(navigator.appVersion);
	if (browserVer >=3) version = "n3";
	else version = "n2";
	
	var field = null;
	
	function format(expr, decplaces){
		var str=0;
		str = "" + Math.ceil(eval(expr)*Math.pow(10,decplaces));
		//str = Math.ceil(str);
		while (str.length <= decplaces){
			str = "0" + str;
			}
		var decpoint = str.length - decplaces;
		return str.substring(0,decpoint) + "." + str.substring(decpoint,str.length);
		}
	
	
	function paysum(APR, time, loan_amt)
	{
	
		  var base = APR / 1200;
		  var base2 = 1;
		  var mbase = 1 + base;
		  for (i=0; i<time; i++)
		  {
		    base2 = base2 * mbase
		  }
		  var pay = loan_amt * base / ( 1 - (1/base2));
		  return format(pay, 2);
	
	}	
	
	function lengthsum(f)
	{
	  var base = f.APR.value / 1200;
	  var mbase = 1 + base;
	  var p = f.payment.value;
	  var amt = f.loan_amt.value;
	  var ln1 = (Math.log(p/(p - (amt*base))));
	  var ln2 = (Math.log(mbase));
	  var lgth = ln1/ln2;
	  if (p - (amt*base) > 0)
	  	{ 
	  	f.result.value = Math.ceil(lgth) + " months";
		}
	  else 
	  	{
		alert ("You cannot pay off a loan of $" + f.loan_amt.value + "\nat " + f.APR.value +"% interest by paying $" + f.payment.value +" per month. \nPlease choose a larger monthly payment.");
		f.payment.value = "";
		return false;
		}
	}
	
	function isnumeric1(f) {
		    nums = /[\0-9]/;
	        if(nums.test(f.APR.value) && f.APR.value >= 1)
	            return true;	
			else
				alert ("Please use a number greater than 1 for the Annual Percentage Rate.");
				f.APR.value = "";
				//f.APR.focus();
				return false;
	    }
		
	function isnumeric2(f) {
		    nums = /[\0-9]/;
	        if(nums.test(f.loan_amt.value) && f.loan_amt.value > 0){
	            return true;
				}		
			else{
				alert ("Please use positive numbers only for the Loan Amount.");
				f.loan_amt.value = "";
				//f.lngth.focus();
				return false;
				}
	    }
		
	function slctfield1(f) {
		f.result.value = "see below";
		if (f.lngth.value == "see below")
			{
			f.lngth.value = "";
			}
		f.variable.value = "1";
		}
	
	function slctfield2(f) {
		f.lngth.value = "see below";
		if (f.result.value == "see below")
			{
			f.result.value = "";
			}
		f.variable.value = "2";
		}
	
	
	function dosum(f) 
		{
		if (f.APR.value == "")
			{
			alert ("Please use a number greater than 1 for the Annual Percentage Rate.");
			f.APR.focus();
			return false;
			}
		
		else if (f.loan_amt.value == "")
			{
			alert ("Please use numbers only for the Loan Amount.");
			f.loan_amt.focus();
			return false;
			}
			
		else 
			{
	
			if (f.variable.value == "1")
				{
				nums = /[\0-9]/;
				if (nums.test(f.lngth.value) && f.lngth.value > 0)
					{
					f.result.value = paysum(f.APR.value, f.lngth.value, f.loan_amt.value);
					}
				else 
					{
					alert ("please enter a number for Length of Loan");
					f.lngth.value = "";
					}
				}
				
			else if (f.variable.value == "2")
				{
				nums = /[\0-9]/;
				if (nums.test(f.payment.value) && f.payment.value > 0)
					{
					lengthsum();
					}
				else
					{
					alert ("please enter a number for Monthly Payment");
					f.payment.value = "";
					}
					
				}
			}
				
		}