Link Button Image Not Visible After Postback?

I have a link button with image and label inside it. After postback, the image and label is not visible.

< asp:LinkButton ID="AddNewRunLinkButton" runat="server" CssClass="Navigationlocalnav"
OnClick="AddNewRunLinkButton_Click" >
< img id="Img1" src="../../Images/add_newIcon.gif" runat="server" alt="Add New Run" />
< asp:Label ID="addText" Text=" Add New Run" runat="server">
< /asp:LinkButton>

This link button is used to import/export data. I have added an attribute on click of this link button(AddNewRunLinkButton) to display a progress bar using javascript - SetInterval function. If I remove this attribute, the image and label is getting displayed, otherwise only link button is getting displayed.

AddNewRunLinkButton.attributes.add("onclick","javascript:DisplayProgress()");
function DisplayProgress()
{
timeid = setInterval("addBlock",100)
}
function Addblock()
{
// Display a progress bar as follows - Increase the width of a div tag at this interval
}