Excel Window problem

Hello Everybody,
I need your valuable suggestions for my problem.
I have one JSP application, which opens MS Excel file in browser window and writes into it. The JSP file, which does this, is being called from other JSP file (Will call this as First JSP file). In first JSP, I am doing following,
I am using POST method here. All parameters are being passed as hidden.
I am submitting the page in first JSP file as follows through javascript on clicking button.
//code here ……
windowPath =' ….‘; //Path of second JSP file goes here
document.markets.action = windowPath;
document.markets.submit();
window.close();
//Code Here ….
Executing this code, second JSP is called which opens MS Excel file in other browser window and writes into it. The first JSP is closed now. The problem here is that two Excel window is being
Opened instead of one. One with data has written in it and other blank Excel window.
Previously I was using GET method. It works fine with GET. But due to limitation of Query String I am forced to used POST method. With POST method, it opens one blank Excel window extra.
Can anyone help me to get rid of other Excel window being opened?
Thanks in advance and sorry for long explanation.
Himanshu

Sorry Everyone,
In Code,
document.markets.action = windowPath;
document.markets.submit();
Here, "markets" is FORM NAME.
Himanshu