How to set setfocus property in web User Control?

Hi guys,
 I want to set SetFocus property for controls in my user control but its not possible.
The error message is: "SetFocus  is not a member of 'class name' " ----> and the 'class name' type is 'User Control'

 Could any one help me how to set this property?
 
Thanks alot
 
shadi
 
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