In my webform i have one Pannel control pannel id=Pannel1.....
from AJAX exten control i am taking one roundedCornerExtender.. and TargetControlId=Pannel1..(to show round corner of Pannel1)
inside that pannel1 i am puting one UpdatePanel and insite UpdatePannel i put one TextBox1 and writting event of textBox1_changedevent()
But it showing error Object Reference not set to an instance of an object..
Why this error is comming..??
how to solve this..