A couple of questions about using onClientClick to save set values for textboxes and labels and then pick them up in codebehind

If I have 3 asp.net controls, a butoon, a label, and a textbox, and if I set a text (innerHTML) value for the label and textbox with the onClientClick event of the button., will the text propeties of the label and textbox retain themselves on postback where I can pick them up in codebehind.
For some reason, after setting the values in javascript successfully, the values disapear when there is a postback. 
Thanks
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