How to prevent auto redirect of drop down menu?

[devil_vin]

Hi..guys!I have a drop down menu with javascript null validation.However,instead of clicking submit button,it will immediately auto redirect after option was selected.Is it possible to prevent this kind of fast respond?

<select name="rNumber" title="number of ticket"
					 onChange="GoToNextPage(this.value)">
                      <option selected>Select</option>
                      <option>01</option>
                      <option>02</option>
                      <option>03</option>
                      <option>04</option>
                      <option>05</option>
                      <option>06</option>
 </select>

<script language="JavaScript" type="text/JavaScript">
    function validate(which) {
        var selects = which.getElementsByTagName('select');
        var radios = which.getElementsByTagName('input');
        for(sel = 0; sel < selects.length; sel++) {
            if(selects[sel].options[selects[sel].selectedIndex].text == 'Select') {
                alert('Please select number of ticket!');
                return false;
            }
        }

        var rselCount = 0;
        for(radio = 0; radio < radios.length; radio++) {
            if(radios[radio].checked) {
              rselCount++;
            }
        }

        if(rselCount == 0) {
           alert('Please select screening time!');
           return false;
        }
        return true;
    }
    
   function GoToNextPage(value){
        if(value != ""){
       document.location = 'reservation3.php?selected_no_ticket=' + value;
  }
}

<form action="reservation3.php" method="post" name="movieList" 
onSubmit="return validate(this);">

And also when onchange mixed with onsubmit,the validation can't execute
alert('Please select screening time!'); when radio button was not selected.What went wrong in the script?Thanks...

[jscheuer1]

At the very least, you need to get rid of this:

onChange="GoToNextPage(this.value)"