How to get value from controls outside current object sender?

Say I have a control with auto post back on and calling txbname_ontextchanged(object sender, EventArgs e)
in txbname_ontextchanged, I can get the text field value. But what if I wanna get other control's value? For example txbaddress value, inside this event handler? I tried to tracing it in the event, but the value that I am getting for other control is not the same as what it appears on the interface front end.
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