Postback Problem

Hi All,
In my application when i click submit button at that time data is inserted in the databse. But when i multiple click submit button then again same data is inserted again in databse.It is creating problem for me.
So i want to Prevent user from double click the submit button.
In short i want when user first time click submit button at that time only data should inseted in the database .If the user continiously Click Submit button at that time data should not enter in database.
How i can achieve this?
The detailed procedure in c# is appriciated.

Thanks in advance.

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