i have a webform , in that webform there r 2 controls, 1. dropdownlist 2. textbox. initially the textbox is in hidden status. whenever the user selected the "NEW" option in the dropdownlist.. i like to show up the textbox and allow the user to enter the data.if the user again select some other option .. i like to hide the text box... do the show & hide the text box without refreshing the page.