how to change selected text in dropdown list in java script

subhashyadav.smec@gmail.com wrote:

where the drop down is blank and i have only item of dropdown not index

This is really very confusing, if the dropdown is blank how you want to select any thing :)

subhashyadav.smec@gmail.com wrote:

how to change selected text in dropdown list in java script at run time

For this Let’s take following example

<asp:DropDownList ID="ddlTest" runat="server">
            <asp:ListItem Text="One" Value="1"></asp:ListItem>
            <asp:ListItem Text="Two" Value="2"></asp:ListItem>
            <asp:ListItem Text="Three" Value="3"></asp:ListItem>
        </asp:DropDownList>

If you know the value in that case your can directely select the drop down like following.

document.getElementById("ddlTest").value = 2;

If you have text and you want to select the dropdown list in that case you need to loop the dropdown list as following.

<script language="javascript">
        function setSelectedIndex(ddl, txt) {
            for (var i = 0; i < ddl.options.length; i++) {
                if (ddl.options[i].text == txt) {
                    ddl.options[i].selected = true;
                    return;
                }
            }
        }
    </script>

And you can call this method as follwong.

setSelectedIndex(document.getElementById("ddlTest"), "Two");