how do i check if the value of a variable (integer) is inside a range for example 300-500?

What language?
Conceptually, in all languages, it's something like:
(a >= 300) and (a <= 500)

Considering this is the PHP and MySQL forum, I'm guessing vegancoder wants to know how to do this in PHP.

This code will work:
if (($myvariable >= 300) && ($myvariable <= 500)) {
// your code goes here
}

Originally Posted by OtterBob

Considering this is the PHP and MySQL forum, I'm guessing vegancoder wants to know how to do this in PHP.

Maybe he means MySQL:

SELECT * FROM table WHERE num>='300' AND num<='500';