Safe data passed into Membership.GetUser(String username).

I created my own password recover control, and I'm curious about the safety of this.  Is it safe to say, Membership.GetUser(textbox1.text)?
 
 In other words,  does GetUser() protect from sql injection or cross site scripting?
 
Is there a premade method that I can call to make user input "safe"?  
 
Thanks,

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