clear textbox on submit button without reloading the page

Question

Below is the jquery and the two code lines one for the text box and the other for the submit button but i just cant get them to link. I have tried a few different ways suggested on here but i cannot get the submit button to link to the text box and clear it. All help greatly appreciated

$j is set as noConflict()

$j('.submit').keypress(function(){
    $j('.comment').val('');
});

<textarea name="name" rows="5" class="fullinput" id="comment"></textarea> 
<input id="submit" type="submit" value="Add to List" class="add" />

UPDATE - So i realised that i was using the incorrect selectors the correct code should have been.

$j('#submit').click(function(event){
  $j('#comment').val('');
  event.preventDefault();
});

This along with the answers below resolved this issue.

Answer 1

This should work:

$j('#submit').click(function(event){
    $j('#comment').val('');
    event.preventDefault();
});

By clicking on a "submit" input, the user is invoking a postback. Therefore you need to use the built-in javascript event to prevent the postback from happening using the .preventDefault() method.