function Zoom(xlink,x,y){
		x1=x+20;
		y1=y+40;
		window.open(xlink,'','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,height='+y1+',width='+x1);
	}
	
	function checkVisibility(id) {
		
		var block = document.getElementById('block' + id);
		var treeimg = document.images('treeimg' + id);
		
		if (block.style.display == 'none') {
			block.style.display = 'block';
			treeimg.src = imgOut.src;
		} else {
			block.style.display = 'none';
			treeimg.src = imgOver.src;
		}
	}
	
	function Check(element, quantity) {

		if (element.value<0) element.value=element.value*-1;
		if (isNaN(element.value) || (element.value=='-') || (element.value>quantity)) {
			element.value = element.getAttribute('last-acceptable-value');
		} else if (element.value=='') {
			element.value = '0';
		} else {
			element.setAttribute('last-acceptable-value', element.value);
		}
		
		return true;
		
	}
	
	function imgPreload(imgOverSrc, imgOutSrc) {
		imgOver = new Image();
		imgOver.src = imgOverSrc;
		imgOut = new Image();
		imgOut.src = imgOutSrc;	
	}
	
	function imgover(imgname) {
		imgname.src = imgOver.src;
	}
	
	function imgout(imgname) {
		imgname.src = imgOut.src;
	}