Pass function parameters from onchange to JavaScript function

Question

Okay I'm currently using AJAX to update part of my site when a drop down box is changed, but I'm having trouble passing the parameters to be usable by the function.

Here is the HTML:

<script type='text/javascript' src='ajax.js'></script> //Where to find function

<div id="combobox" style="width: 150px; height: 300px; overflow-y: scroll">
  <select onchange="MakeRequest(test); location = this.options[this.selectedIndex].value;"> 
    <option>Races</option>

    <?php ComboBox() ?>
  </select>
   .
   .

Here is the AJAX function in external ajax.js file:

function MakeRequest(test) {
  var linkInfo = "teleport.php?call=" + test;
  var xmlHttp = getXMLHttp();

  xmlHttp.onreadystatechange = function() {
    if (xmlHttp.readyState == 4) {
      HandleResponse(xmlHttp.responseText);
    }
  }

  xmlHttp.open("GET", linkInfo, true);
  xmlHttp.send(null);
}

How would I get this working?

Niet the Dark Absol · Accepted Answer · 2012-05-30 17:50:38Z

1

location=this.options[this.selectedIndex].value

This is changing the page to a different location. That is not AJAX, remove it.

Instead, put that this.options[this.selectedIndex].value (or just this.value - same thing) what you put test.

answered May 30, 2012 at 17:50

Niet the Dark Absol

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Comments

Saeed Neamati · Accepted Answer · 2012-05-31 05:22:32Z

0

Ajax nature is asynchronous. I guess you want to first send an AJAX request to the server, and on the result of its response, redirect user on the client side to another page.

What happens in your code, is that first of all, MakeRequest() function is called, but it's immediately returned back (because ajax is asynchronouse), thus the next part of the onchange attribute would be called, and user would be redirected to another page.

To test, make your ajax call synchronous. See here.

answered May 31, 2012 at 5:22

Saeed Neamati

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Comments

Cauly · Accepted Answer · 2012-05-31 05:30:16Z

0

<select onchange="MakeRequest(this.value); " />

answered May 31, 2012 at 5:30

Cauly

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