Asp javascript implements the method of saving data when closing a window

How to save data when closing the window <SCRIPT language="javascript">
function IfWindowClosed() 
{ 
var win = null; 
try 
{ 
 = "ss"; 
if (  != "ss" ) 
{ 
win = ("","","width=100,height=100,left=10000,top=10000"); 
("();",0); 
} 
 = ""; 
} 
catch(e) 
{ 
win = ("","","width=100,height=100,left=10000,top=10000"); 
("();",0); 
} 
} 
 
("IfWindowClosed()",100); 
("();",510); 
</SCRIPT> 
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Open the above file using the onunload event

To save the data file, the above file is used to detect whether the window is closed or refreshed.

IE5 is compatible. I used to judge before that IE5 does not support the closed attribute.
The above code has been tested many times and no problems have been found yet