Shell Programming and Scripting

Hi, I'm trying to check to see that the arguments given to my script are both numeric and positive integers. I'm using tcsh. I figured out the positive part, but I am having trouble with the arguments being numeric and integers
I have no idea where to get started with the checking them actually being numbers...could someone point me in the right direction?
As for the integer part, this is currently what I have written:
@ int = 1
if ( $argv[1] % $int != 0 ) then
echo "not an integer"
endif

However, when this is executed, I get the error message of
if: Badly formed number.

Can if statements only take integers? If so, how can I check to see that the given argument is an integer?

I don't know about tcsh, but bash has different comparison operators for numbers and strings. So, by applying an arithmetic comparison, I will receive an error message if the operands are strings.
In code:
[code]
#!/bin/bash

if [ $1 -eq $1 2>/dev/null ]; then
echo Is number
else
echo Is NOT a number
fi