function validate_qty(id) {
	var objRegExp  = /(^-?\d\d*$)/;
	qty_value=document.getElementById("qty"+id).value;
	avail_qty_value=document.getElementById("avail_qty"+id).value;
	aaaa=objRegExp.test(qty_value);
	if (objRegExp.test(qty_value)) {
		if(qty_value<0) {
			alert("Quantity to buy must be positive number!");
			document.getElementById("qty"+id).focus();
			document.getElementById("qty"+id).value=0;
		}			
		if((qty_value-avail_qty_value)>0) {
			alert("Quantity to buy can not exceed available quantity!");
			document.getElementById("qty"+id).value=avail_qty_value;
			document.getElementById("qty"+id).focus();
		}	
	}
	else {
		alert("Quantity to buy is not valid number!");
		document.getElementById("qty"+id).focus();		
		document.getElementById("qty"+id).value=1;
	}
}
function open_window1(url) {
mywin = window.open(url,"win",'toolbar=0,location=1,directories=0,status=0,menubar=1,scrollbars=1,resizable=0,width=480,height=480');
}
function show_product_details(what_to_display) {
	aaa=what_to_display;
	if (aaa=="Features") {
		document.getElementById("Features").style.display="block";	
		document.getElementById("Specification").style.display="none";	
		document.getElementById("Contents").style.display="none";	
		document.getElementById("link1").style.font="bold 11px Arial";
		document.getElementById("link2").style.font="normal 11px Arial";
		document.getElementById("link3").style.font="normal 11px Arial";
	}
	if (aaa=="Specification") {
		document.getElementById("Features").style.display="none";	
		document.getElementById("Specification").style.display="block";	
		document.getElementById("Contents").style.display="none";	
		document.getElementById("link1").style.font="normal 11px Arial";
		document.getElementById("link2").style.font="bold 11px Arial";
		document.getElementById("link3").style.font="normal 11px Arial";
	}
	if (aaa=="Contents") {
		document.getElementById("Features").style.display="none";	
		document.getElementById("Specification").style.display="none";	
		document.getElementById("Contents").style.display="block";	
		document.getElementById("link1").style.font="normal 11px Arial";
		document.getElementById("link2").style.font="normal 11px Arial";
		document.getElementById("link3").style.font="bold 11px Arial";
	}
}