Text is not Displaying

Hai

I am trying to fill one textbox with some concatenated  string fetched from  database on leave of another textbox and this is using in many forms.So i want to make it common function. I wrote  a function in common class like

 public void FillpartyAddress(string Partycode, TextBox txtAddress)
 {

 string strAddress;

// some codes.

txtaddress.text=strAddresss.

}

My problem is While running ,the corresponding textbox is empty. i check the text of the corresponding textbox text after calling this function, it has some text but when the form load its not there.

Please some one help me

thanks