Admin panel Ajax request value disappears

Question

I'm trying to retrieve a value from the mysql db to be posted to a textbox on the admin panel.

I have everything working and connecting and returning the correct values. When I step through the debugger, I see the values being assigned to the correct variables etc.

Problem I'm experiencing however, is that the values I retrieve, seem to disappear from the textbox after the function has finished processing.

phtml code:

function valChecker()
{

  var val = document.getElementById("test_attrib").value;

var url = '<? echo Mage::helper('adminhtml')->getUrl('machines/index/death'); ?>';

var response = "";

 new Ajax.Request(url, {
                    parameters:{test_attrib:val},
                onSuccess: function(transport){ 

        response = transport.responseText;
        document.getElementById("test_attrib").value = response;

                },
                  onFailure:  function(failer){
                  }
             });

}

if anyone would be so kind to assist please?

Answer 1

Try to set textbox value on AJAX onSuccess callback. Please find revised code as below:

var url = '<?echo Mage::helper('adminhtml')>getUrl('machines/index/death');?>'; 

var response = "";

new Ajax.Request(url, {
    parameters:{test_attrib:val},
    onSuccess: function(transport){ 
        response = transport.responseText;
        document.getElementById("test_attrib").value = response;
    },
    onFailure:  function(failer){
    }
});

It should worked.