Problem with ajax updatepanel
I am facing a problem ...I am using requiredfieldvalidator for dropdownlist and regularexpressionvalidator for textbox entering email address all these controls are placed in updatepanel(ajax)....first time error messages can see ..but after selecting one item from dropdownlist error message can't see but actual validation are taken place in the background...
how can i solve this..ie. how to show error messages while something failed,,,
please help me