The compile error I'm getting is "newline in constant"
The error occurs where the four asterisks are (****).
I can't debug, because the solution won't build successfully.

<script type="text/javascript">
function TNClicked(fullImgURL, TNID) {
    document.getElementById("<%= this.imgFull.ClientID %>").src = fullImgURL;

    var pnlFullImage = document.getElementById("<%= this.pnlFullImage.ClientID %>");
    if (pnlFullImage.style.visibility != "visible")
        pnlFullImage.style.visibility = "visible";

    document.getElementById("<%= this.tcImage.ClientID %>").innerHTML = TNID;
    //document.forms[0].ctl00$ctl00$ctl00$cntBody$hfImage.value = TNID;
    //****document.getElementById("<%= this.hfImage").setAttribute("value", TNID);
    //document.getElementById("<%= this.hfImage.ClientID %>").value = TNID;
}
</script>