Question

I have the below code in a .ascx file as part of an asp.net project. How can I write the JavaScript to change the image source to a gif?

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="Steps123.ascx.cs" Inherits="SwintonTaxiWeb.UserControls.Steps123" %>

<div id="slickShow">

    <div class="<%=stepOneDivClass %>">
            <asp:ImageButton runat="server" ID="GetQuote" 
                CssClass="imgBut swapImage {src: '/images/Quote-Oval-button-(roll-over).png'}"
                ImageUrl="/images/Quote-Oval-button.png" AlternateText="Get Quote" TabIndex="1" />
    </div>
    <div id="rollOver">
        <img src="/images/Roll-over-to-view-steps-two-and-three.png" alt="Roll over to view steps 2 and 3" />
    </div>
    <div id="slideContainer">
        <div class="step-two">
            <asp:ImageButton runat="server" ID="GetCallback" 
                CssClass="swapImage {src: '/images/Call-back-button-(roll-over).png'}" 
                ImageUrl="/images/Call-back-button.png" AlternateText="Get Callback" Width="69" 
                Height="44" TabIndex="2" />
        </div>
        <div class="step-three">
            <fieldset>
                <asp:TextBox CssClass="postcode" ID="postcode" runat="server" TabIndex="0" /><asp:ImageButton runat="server" 
                    ID="go" CssClass="go" ImageUrl="/images/Go-button.png" AlternateText="Go" onclick="Go_Click" TabIndex="1" />
            </fieldset>      
        </div>
    </div>
</div>

Answer 1

Using just JavaScript you could do:

var image = document.getElementById('ctl00_MainContent_tester_GetQuote');
image.src = [path to gif];

You could also use jQuery to grab the element via class (or some other selector if you want):

var image = $('.[ClassOfImage]').attr('src', '[NewPathToGif]');

I love the jQuery.