<!-- 
function openwindow( url, winName, width, height) 
{ 
xposition=0; yposition=0; 
if ((parseInt(navigator.appVersion) >= 4 )) 
{ 
xposition = (screen.width - width) / 2; 
yposition = (screen.height - height) / 2; 
} 
theproperty= "width=" + width + "," 
+ "height=" + height + "," 
+ "location=0," 
+ "menubar=0," 
+ "resizable=1," 
+ "scrollbars=1," 
+ "status=0," 
+ "titlebar=0," 
+ "toolbar=0," 
+ "hotkeys=0," 
+ "screenx=" + xposition + "," //仅适用于Netscape 
+ "screeny=" + yposition + "," //仅适用于Netscape 
+ "left=" + xposition + "," //IE 
+ "top=" + yposition; //IE 
window.open( url,winName,theproperty ); 
} 
//-->