PHP

I am taking a Web Development class and brand new to PHP

I am running a WAMP server on my local machine

When I run my code from my WAMP server everything runs fine, but when I upload my code to the school's server I run into a problem:

the if(isset($_POST['submit']){

//run code

}

else{

echo "uh oh something went wrong";

}

the else portion is being ran. any ideas what can be wrong? i know these are very vague since i am not providing the actual code