Dynamic Drop Down Menu

[snh]

Hello,

I have a coded two drop down boxes which pull information from a MySQL database. I am currently using a javascript jump menu to refresh the page, which then generates the second drop down box (based on the selection in the first drop down box). My question is that when the page refreshes all my previous data is lost. This might be a question for a java script person, but do you know of any way in which I can retain my values within the rest of my form? Any suggestions would be great! Thanks

Here is the jump menu code I am using:

    <script language="JavaScript" type="text/JavaScript">
    <!--
    function MM_jumpMenu(targ,selObj,restore){ //v3.0
      eval(targ+".location='"+"Pratt_Instance_1.php?mcate="+selObj.options[selObj.selectedIndex].value+"&mind="+selObj.selectedIndex+"'");
      if (restore) selObj.selectedIndex=0;
    }
    function MM_jumpMenu2(targ,selObj,restore){ //v3.0
    eval(targ+".location='"+"Pratt_Instance_1.php?mcate="+selObj.options[selObj.selectedIndex].value+"&mind="+selObj.selectedIndex+"$cate="+selObj.options[selObj.selectedIndex].value+"&ind="+selObj.selectedIndex);
      if (restore) selObj.selectedIndex=0;
    }
    //-->
    </script>

and the drop down box SQL code

    <select id="Instance_Type111" name="mcate" onchange="MM_jumpMenu('parent',this,0)">
                <option value="0">Select</option>
    <?php

            // Get the Categories from Database
            if (!isset($type_array)){
             $type_array=get_category_name();

            $query = "SELECT Type_ID, Type_Name FROM Instance_Type111";
               $query_result=@mysql_query($query,$mysql_link)
                     or die ('Could not get categories! <br>\n');
               $type_array = db_result_to_array($query_result);
               }
         // Display Categories in the menu listing
            $mi=1;
            foreach ($type_array as $row){
            $Type_ID= (string) $row['Type_ID'];
            $Type_Name= $row['Type_Name'];
            if ($mi!=$mind){
            print ("<option value=$Type_ID>$Type_Name</option>");
            } else {
            print ("<option value=$Type_ID selected>$Type_Name</option>");
            }
                 $mi++;
            }

            // Setting the main category code
      // $mcate_code is the maincat_id of main category chosen
         if(!isset($HTTP_GET_VARS['mcate']))   {
           $mcade_code = 0;
          } else{
           $mcade_code =  $HTTP_GET_VARS['mcate'];
         }
?></select></td>
               </tr>
<tr>
<td>
Detailed Incident Type:
</td>
<td >
<select name="cate" id="Detailed_Instance_LUT111" onChange="MM_jumpMenu2('parent',this,0)">
<option value="0"  >Select</option>
   <?php
//Get Detailed Definition from Database
   $type_array=get_categories($mcade_code);
// Display Categories in the menu listing
   display_category($type_array);

// Setting the main category code
      // $cate_code is the maincat_id of main category chosen
         if(!isset($HTTP_GET_VARS['cate']))   {
           $icade_code = 0;
          } else{
           $icade_code =  $HTTP_GET_VARS['cate'];
         }
?></select></td>

Thanks

[_uk_stuff]

Hi,

You could pass the selected variable into the address of the page once selected and then using JavaScript reselect the initial selected item.

Alternatively you could use AJAX to populate the second drop down based on the first without the need to refresh the page. This would be a better solution in my opinion.

If you wanted to learn a bit about AJAX try this link out... its where I started;

http://www.tizag.com/ajaxTutorial/ajax-mysql-database.php

Cheers

[snh]

Thanks Ill try that out!