var num_str = '0123456789';
function isNumeric(x) {
	if (x.length>1) {
		for (var i=0;i<x.length;i++) {
			var j=isNumeric(x.substring(i,i+1));
			if (!j) {
				return j;
			}
	    }
		return j;
	}
	else {
	    if (num_str.indexOf(x)>=0) {
			return true;
		}
		return false;
	}
}

function getArgs() {
	// FromO'Reilly's JavaScript - The Definitive Guide
	var args = new Object();
	var query = location.search.substring(1);
	var pairs = query.split("&");
	for (var i=0;i < pairs.length;i++) {
		var pos = pairs[i].indexOf('=');
		if (pos == -1) continue;
		var argname = pairs[i].substring(0,pos);
		var value = pairs[i].substring(pos+1);
		args[argname] = unescape(value);
	} 
	return args;
}

function getOpt(s) {

	var i=s.indexOf('-');
	//check for - in product code - removed following to just always grab from first -
	//if (s.indexOf('-',i+1)>-1) {
	//	i=s.indexOf('-',i+1);
	//}
	return s.substring(i+1);
}

function changeClass(id,newClass) {
	document.getElementById(id).className=newClass;
}

function changeOpt(idx) {
	//unselect old thumb
	changeClass("opt_"+g_selOpt,"");
	var bulktxt_front='<br />(Bulk price for ' + BULK_PRICE_MIN + ' yards or more: ';
	var bulktxt_back=')';
	
	//change thumb to selected
	changeClass("opt_"+idx,"selected");
	g_selOpt=idx;

	//show correct selected image
	document.getElementById('sel_img').src = g_imgPath + prod_arr[idx].img;

	writeLayer('prod_code',base_code+"-"+prod_arr[idx].pcode);
	writeLayer('prod_style',prod_arr[idx].pstyle);
	
	var pricetxt=prod_arr[idx].price + ' ' + item_type;
	if (prod_arr[idx].bulk_price) {
		pricetxt+=bulktxt_front + prod_arr[idx].bulk_price + ' ' + item_type + bulktxt_back;
	}
	writeLayer('prod_price',pricetxt);
	
	
	if (prod_arr[idx].avail==2) {
		writeLayer('prod_avail','In Stock');
	} else if (prod_arr[idx].avail==1) {
		writeLayer('prod_avail','<strong>Backordered</strong>');
	} else {
		writeLayer('prod_avail','<strong>Discontinued</strong>');
	}
	window.scroll(0,0);
	if (document.getElementById("quan")) {
		document.getElementById('quan').focus();
	}
}

//text change function
function writeLayer(layerID,txt){
	if(document.getElementById){
		document.getElementById(layerID).innerHTML=txt;
	}
	else if(document.all){
		document.all[layerID].innerHTML=txt;
	}
	else if(document.layers){
		with(document.layers[layerID].document){
			open();
			write(txt);
			close();
		}
	}
}