Can I use For-loop,Do while statements under Xilinx's ISE?

[Balamurugan]

I have used if statements for most of the case. Now I have seen the use of "For-loop and While loop" under templates in XILINX ISE8.2 which uses xst synthesizer. But when I write program using "for-loop", I didn't get the output or rather that looping isn't executing at all. I did write in perfect procedure. Currently I'm only able to use "If-Else, when-Case" statements. Is ther any other statements which I can use in xilinx xst?. Please note me out. Thankz