protected void DDLAirportSelection_SelectedIndexChanged(object sender, EventArgs e)
if (DDLCollegeSelection.SelectedItem.Value == "Siddharta Engineering College")
else if (DDLCollegeSelection.SelectedItem.Value == "Shadan Engineering College")
else if(DDLCollegeSelection.SelectedItem.Value == "HiPoint Engineering College");
and in goal page use this in page load event :
with an if statement ,check Querystring and do any operation you want .
In Addition :
if you have 2 or more data to send as querystring, use & between any querystring variable;
you cant use space between words in querystring so use 20% or + or use fit encoding .
in our example you can use another name instead of Querystring as querystring field.