function IsNumeric(sText)

{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
   
   }




function bob(){
	var out = 0;

	
	
	
if (document.getElementById('dist1').value != 0) {
	//calc if km selected
	var a = document.getElementById('dist1').value;
	var b = document.getElementById('time').value;
	
	out = b / (a * .00062137);

}
else {
	//calc from text field
	var a = document.getElementById('dist2').value;
	var b = document.getElementById('time').value;
	
	if (document.calc.units[1].checked == true){
		a = a * .62137;
	}
	
	out =  b/ a ;

}
	
	if (!isNaN(parseInt(out)) && IsNumeric(out)){
	var mins = parseInt(out);
	var secs = parseInt(out % 1 * 60);
	document.getElementById('test').innerHTML = mins + " Minute " + secs + " Second Miles";
	}
	else{
		document.getElementById('test').innerHTML = "Please enter numeric time and distance";
	}
}