binary to integer conversion code

I wrote a simple program to converting 4bit binary to integer and
display the same on my 7 segment leds.
my program got synthesized and mapped and placed and routed . but when
i tried to run this program on my spartan2 kit it shows
different figures on the 7 segment display everytime i give the same
binary number in the input.

it doesnt show correct integer. while when i try to run other programs
they work fine.