Question

I try this and it gives the error mentioned in the title at the line I call String.Format.

public static void JqueryDialogue(string divId)
{
    String script = String.Format(
        "$(document).ready(function(){ $('#{0}').dialog('open'); });", 
        divId);

    // Gets the executing web page
    Page page = HttpContext.Current.CurrentHandler as Page;
    string codeId = "openDialoge" + divId.ToString();

    // Checks if the handler is a Page and that the script isn't already on Page
    if (page != null && !page.ClientScript.IsClientScriptBlockRegistered(codeId))
    {
        page.ClientScript.RegisterStartupScript(
            typeof(JavascriptHelper), 
            codeId, 
            script,
            true);
    }
} 

Answer 1

If you use String.Format you’ll need to escape the { and } characters that you want to be outputted literally since they are Javascript code. To achieve this you use {{ and }} respectively.

You can read more about string formatting here where an odd behavior resulting from escaping curly braces is also explained.