<div id="selDiv" style=" z-index:100; visibility:visible; clip:rect(0px 110px 80px 92px); position:absolute"><%--left:279px; top:167px"--%> <asp:DropDownList ID="workerno_list" runat="server" style="z-index:-1" Width="110px" ></asp:DropDownList> </div> <asp:TextBox ID="workerno_value" runat="server" style=" z-index:103px; position:absolute" Font-Size="10" Width="93px" MaxLength ="50" Height="22px"></asp:TextBox> <script> function addTxtTanto(va) { document.getElementById("workerno_value").value=va; document.getElementById("workerno_value").select(); } </script>

page_load() { if (!IsPostBack) { workerno_list.Attributes["onchange"] = "addTxtTanto(this.options[selectedIndex].innerText)"; } }