SPWeb is undefined

Question

I am a newbie in sharepoint and only for 1 month. I am using sharepoint 2007,.aspx. and doing for an email form with some validation, after user pass the validation the email send.
But I'm getting the error thisWeb is undefined, I create this inside javascript function. I have SPUtility.js and I try to add line like SPWeb thisWeb = site.OpenWeb(SPContext.Current.Web.ID; and this causes my whole function not working. Do I need some .js for SPWeb? Please give me some instruction.

Here is my code:

<script type="text/javascript">
function notEmpty(){
    var txt="";
    var myTo= document.getElementById('txtTo2');
    var myName= document.getElementById('txtName2');
    var myFrom= document.getElementById('txtFrom2');
    var myBody= document.getElementById('txtBody2');
    var sendButton = document.getElementById('sendEmail');
    var validateButton = document.getElementById('button1');

    var body = ("This email is send from : "+ myName + ", Note here : " +myBody);

    var mailformat = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;


    if(myTo.value==""||myName.value==""||myFrom.value==""||myBody.value=="")
    {
        alert("Please Fill In All Fields!");
        return false;

    }
    else if(!(myTo.value.match(mailformat))||!(myFrom.value.match(mailformat)))
    {
        alert("Invalid Email Address!");
        return false;
    } 
    else if(myBody.value.length >5 )
    {
        alert("Please check body field! 5 characters only");
        return false;
    }
    else 
    {
        try
        {
            SPUtility.SendEmail(thisWeb, true, false, myTo, myFrom, body);                                                     
            alert(EmailSend!");
        }
        catch(err)
        {
            txt="There was an error on this page.\n\n";
            txt+="Error description: " + err.message + "\n\n";
            txt+="Click OK to continue.\n\n";
            alert(txt);
        }
    }
    return true;
}
</script>

Answer 1

On SharePoint2007, you cannot access SharePoint object like SPWeb from JavaScript. Only on SharePoint 2010, the client object model was added that enables interaction with the SPWeb object (see this link)

Specifically, the easiest solution for the problem of sending an email from client side code is wtriting an Ajax callback, the client code uses the callback and the server-side handler calls SPUtility.SendEmail. (See this thread for more solutions)