Question

I have an ASP textbox control where I need to execute some javascript function when the OnClick event occurs. I need to pass to that javascript function two IDs of other controls on that page. My textbox markup is as follows:

<asp:TextBox ID="txtMonthDisplay" runat="server" Style="border-top: none; border-left: none;
border-right: none; border-bottom: solid 1px blue; cursor: pointer; color: Blue;
width: 35px;" EnableViewState="True" MaxLength="3" onClick="javascript: ShowBox('<%= divYear.ClientID%>', '<%= txtYearDisplay.ClientID %>');"></asp:TextBox>

But whenever it calls the javascript function I have setup an alert to check the incoming values, and they are simply <%= txtYearDisplay.ClientID %> and <%= divYear.ClientID%>. Not the actual IDs of those controls.

What am I missing here, or doing incorrectly? I’m not well versed with asp.net so server vs. client side is a bit fuzzy for me.

Thanks

Answer 1

You can’t Response.Write (<%= %> is shorthand for Response.Write) into a server tag (usually).

Instead, you can write your onclick handler in the codebehind:

txtMonthDisplay.Attributes["onclick"] = string.Format(
    "ShowBox('{0}', '{1}');",
    divYear.ClientID,
    txtYearDisplay.ClientID);

By the way, you don’t need the javascript: prefix. That is only necessary when setting the href of a link to execute script. It is not needed for event handlers such as onclick.