function check_form() {
	itags = document.getElementsByTagName("input");
	error_flag = false;
	
	total = 0;
	for (i=0;i<itags.length;i++)
	{
		
		if(isQuantity(itags[i]))
		{
			
			if(isNaN(itags[i].value)) {
				error_flag = true;
				
			}else if(parseInt(itags[i].value) <= 0){
				error_flag = true;
				
			}				
		}
	}
	
	if (!error_flag) {
		proceed();
	} else {
		window.alert("There is a problem with your shopping cart.\n\nTo remove an item, press its trash icon.")
		update();
	}
	
}
function checkInput(e,  el) {
	if (checkEnter(e, el)) {
		return isNumber(e);
	} else {
		window.document.getElementsByName(el)[0].blur();
		return false;
	}
	
}
function isNumber(ev) {
	if (window.event) {		
		return isNum(window.event.keyCode);
	}else if (ev.which) {
		return isNum(ev.which);
	} else {
		return true;
	}
	
}
function isNum (num) {
	switch (num) {
		case 48:
			return true; break;
		case 49:
			return true; break;
		case 50:
			return true; break;
		case 51:
			return true; break;
		case 52:
			return true; break;
		case 53:
			return true; break;
		case 54:
			return true; break;
		case 55:
			return true; break;
		case 56:
			return true; break;
		case 57:
			return true; break;
		default:
			return false;
	}
}
function checkEnter(e,  el) {
	if (window.event) {		
		if(window.event.keyCode == 13) {		
			return false; 
  		} else {  		
  			return true; 
  		}
	}else if (e.which == 13){			
			return false;   	
	}else {		
		return true;
	}
	
}
function proceed() {
	document.thisform.action = "shipping.php";
	document.thisform.submit();
}
function update() {
	document.thisform.action = "cart.php";
	saveScrollCoordinates();
	document.thisform.submit();
}
function isQuantity(tag){
	tname = tag.name.toString();
	if (tname.match('quantity') == 'quantity'){
		return true;
	} else {
		return false;
	}
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}


function saveScrollCoordinates() {
  document.thisform.scrollx.value = (document.all)?document.body.scrollLeft:window.pageXOffset.toString();
  document.thisform.scrolly.value = (document.all)?document.body.scrollTop:window.pageYOffset.toString();
} 
function setQuantity(uid) {
	element = window.document.getElementsByName(uid + '_quantity')[0];
	if(element.value == "0" || element.value == "00") {
		if( window.confirm("Would you like to remove this item?") ) {
			removeItem( uid );
		} else {
			document.thisform.change.value='quantity';
			document.thisform.item.value=uid;
			update();
		}
		
	} else {
		document.thisform.change.value='quantity';
		document.thisform.item.value=uid;
		update();
	}
	
}
function setColor(uid) {
	document.thisform.change.value='color';
	document.thisform.item.value=uid;
	update();
}
function removeItem(uid) {
	document.thisform.change.value='delete';
	document.thisform.item.value=uid;
	update();	
}