How to eliminate duplicate or repeated values on textbox.text
<p>i used ajax control ModalPopupExtender.ModalPopupextender has panel. in that panel, text boxes and gridview placed and OK button. it has three textboxes and gridview and ok button sequentially. While edit button of gridview and after entering the some intextboxes, the text of textboxes repetedly show on textbox with camma. i dont know it is happening please help me </p>
