populate dropdown on selection of other dropdown

Question

I have two drop-down boxes. I want to populate second drop-down box on selection in the first drop-down box. My values are retrieving from database. Is this possible withou

Answer 1

Lets take an easy example, I'm using this for the same purpose that you want and it works perfectly fine.

This is the country dropdown:

Select Country";
        while($clist=mysql_fetch_array($countrylist))
        {
          echo "$clist[Name]"."
";
        }
        echo "";
 ?>

This is the region dropdown:

Now make a seperate file named crlist.js and include it in the page having above code like this:

code for crlist.js:

var request = false;
/*@cc_on @*/
/*@if (@_jscript_version >= 5)
try {
request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e2) {
request = false;
}
}
@end @*/
function fillSelect(country,path) {
var url = path+"crlist.php?country=" + country;
request.open("GET", url, true);
request.onreadystatechange = go;
request.send(null);
}

function go() {
if (request.readyState == 4) {
//if (request.status == 200) {

var response = request.responseText;

var list=document.getElementById("region");
            for (i = list.length - 1; i>=0; i--) {
                list.remove(i);
            }
var records=response.split('|');
for (i=1; i=0; i--) {
                list.remove(i);
            }
        //while (list.childNodes[0]) {
        //list.removeChild(list.childNodes[0]);
        //}
        }
        fillSelect(this.value,path);
        //alert(this.value);

    }
//fillSelect(country.value);
}

Now make a seperate file named crlist.php.

Code for crlist.php:

".$region['Name']."";
}       
?>

Now add following script on the page having dropdowns:

This is my own script, and i've assumed that you have created country and region tables. But you need to tweak the queries and above code according to your db structure.

Reference to my answer: Cascade Dropdown List using jQuery/PHP

Hope this helps.