Simple JS question

If one adds a onClick="function();" to a submit button. Will the JS function be processed before it goes onto the php page that it will ultimately go to?

example:

<form method="post" action="blank.php">
<input type="text">
<input type="submit" onClick="validate();" name="whatever">

Will the validationg take place before the form is sent to the next php page? I think it will, but i wanted to make sure

You can't do it that way to validate before submission. You should call the function in <form onSubmit='....'> tag..

Check this
http://www.yourhtmlsource.com/javascript/formvalidation.html