how to set the OPACITY feature to my asp.net control

[pashitech]

Hi I have created a user control and I am using this user control in loging.aspx my requirement is when user control is desplaying the rest of the page should become dull(I MEAN I WANNA APPLY OPACITY-AS I USED TO DO IN WINforms)but, I am unable to meet this req. in webforms please help me with a solution thanks

prashanth, s/w Engineer, Syfnosys.