Hi, Pal
When ur working with drop down list control u need to understand what is server side code and what is client side code
when u working with dropdown list u simply add AutoPostBack = "True" to the control in the page. that's it when ur change the selected item in list it fires the
ddlCtrl_OnSelectedIndexChanged(object sender, EventArgs e)
event and corosponding code is executed.
For ur problem
Simple Solution is Put the 3 dropdown controls in a updatepanel and write a code like
ddc1_OnSelectedIndexChanged(object sender, EventArgs e)
{
ddc2.datasource = ds1
}
<pr2 lang="cs">ddc2_OnSelectedIndexChanged(object sender, EventArgs e)
{
ddc3.datasource = ds2
}</pr2>
Thanks...