function openWindow(URL) { 
var availHeight = .75*screen.availHeight; 
var availWidth = .95*screen.availWidth; 
var x = 0, y = 0;
var newURL; 
if (document.all) { 
x = window.screenTop; 
y = window.screenLeft; 
} 
else if (document.layers) { 
x = window.screenX; 
y = window.screenY; 
} 
var arguments = 'resizable=1,toolbar=1,location=1,directories=1,addressbar=1,scrollbars=1,status=1,menubar=1,top=0,left=0, screenX='+x+',screenY='+y+',width='+availWidth+',height='+availHeight; 
newURL =  URL.replace("calendar","calendarprt");
newWindow = window.open(URL,'',arguments); 
//alert(availWidth);
}