fvwm modifiers

I have a question about modifiers. I would like to assign the mod1 through mod5 modifiers to particular keys. I installed both xmodmap and xev. So I wanted to compare the output of the two, in order to make sure it is working. However when I run xev and press the left Ctrl key, I get the following output:

On the other hand when I run xmodmap, I get the following:

So in the first case I get keycode 37, while in the second 0x25. Am I reading it correctly? So does that mean that I will need to change the xmodmap bindings?

Thanks a lot in advance.

37 is the decimal value of the keycode. 0x25 is its hexidecimal value. The two values are equal to each other. The same is for all your other keycodes. For example Control_R’s hexidecimal value shown above is 0x69. That corresponds to decimal 105. If you check xmodmap -pke | less and scroll down to keycode 105, you should have a line that reads something like this:

keycode 105 = Control_R NoSymbol Control_R NoSymbol Control_R Control_R