internet explorer javascript error "Syntax error"

Internet Explorer 8

I'm getting the error below only in Internet Explorer browser. it works fine in Chrome, Mozilla. In IE showing this error but works. I open this url via iframe using jquery ui when I post the form I see this error Any idea how to fix it?

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)
Timestamp: Tue, 22 Feb 2011 15:26:35 UTC

Message: Syntax error
Line: 1
Char: 6
Code: 0
URI: https://url.com/page.aspx?chatId=406017938&header=RSA Token Issues/Setups&support=2&param=0

More Details:

Open form

function OpenChatForm(chatid, chatname, support, param){

            $("#ChatForm").dialog("open");          
            $("#modalIframeId").attr("src","page.aspx?chatId=" + chatid + "&header=" + chatname + "&support=" + support + "&param=" + param);
            return false;
        }
    <div id="ChatForm">
            <iframe id="modalIframeId" width="100%" height="100%" marginwidth="0" marginheight="0"
                frameborder="0" scrolling="auto" title="Dialog Title">Your browser does not support</iframe>
        </div>

On submit form

function SubmitForm() {

        var postForm = document.forms[1];   
        postForm.comment1.value = Lbl.GetText();
        postForm.comment2.value = Lbl2.GetText();
        postForm.comment3.value = Lbl3.GetText();
        postFo开发者_如何学Crm.comment4.value = Lbl4.GetText();
        postForm.comment5.value = Lbl5.GetText();

        postForm.submit();  

    }