function validate() 
{
	document.getElementById("errors").innerHTML="";
		
	var a = document.getElementById("adults").value;
	var t = document.getElementById("teenagers").value;
	var c = document.getElementById("children").value;
	var check = 1;
	
	var error = "";
	
	if(a == ""){ a = 0; } else { if (isNaN(a) || a.indexOf('.')==1) { error = error + "Please enter a vaild value for <b>Adults</b><br/>"; check = 0;} }
 	if(t == ""){ t = 0; } else { if (isNaN(t) || t.indexOf('.')==1) { error = error + "Please enter a vaild value for <b>Teenagers</b><br/>"; check = 0;} }
 	if(c == ""){ c = 0; } else { if (isNaN(c) || c.indexOf('.')==1) { error = error + "Please enter a vaild value for <b>Children</b>"; check = 0;} }
 	if( a == 0 && t == 0 && c == 0 ) { error = error + "<b>Please complete the form</b>"; check = 0; }
 	if (check == 1) { calculate(a,t,c); }  else { document.getElementById("errors").innerHTML=error; }
}


function calculate (adults,teens,child)
{
	adults = parseFloat(adults);
	teens = parseFloat(teens);
	child = parseFloat(child);

	for (var i=0; i < document.calc.supply.length; i++){ if (document.calc.supply[i].checked) { var s = document.calc.supply[i].value; } }
		
	document.total.adults.value = adults;
	document.total.teens.value = teens;
	document.total.child.value = child;
	document.total.supply.value = s;
	
	document.total.submit(); 

}