Javascript on forms not working as expected in the browser

Hi,

I have written a javascript on the form "Supply to Production Task" to insert as many rows as the value in the 'Planned Quantity' column. The script works perfectly on running the PDF in PDF preview. But, it doesn't work while I run it in the browser. It just inserts a single row for each material,regardless of the Planned Quantity value. Can somebody help me on this???

Thanks,

Swapna