Disable button on form submission

Question

I have a button that I would like to disable when the form submits to prevent the user submitting multiple times.

I have tried naively disabling the button with java

Answer 1

Building on @rp.'s answer, I modified it to invoke the custom function and either submit and disable on success or "halt" on error:

public static void DisableButtonOnClick(Button ButtonControl, string ClientFunction)
{
    StringBuilder sb = new StringBuilder(128);

    if (!String.IsNullOrEmpty(ClientFunction))
    {
        sb.AppendFormat("if (typeof({0}) == 'function') {{ if ({0}()) {{ {1}; this.disabled=true; return true; }} else {{ return false; }} }};", ClientFunction, ButtonControl.Page.ClientScript.GetPostBackEventReference(ButtonControl, null));
    }
    else
    {
        sb.Append("return true;");
    }

    ButtonControl.Attributes.Add("onclick", sb.ToString());
}