[Solved] How to call Codebehinds Events by using Javascript code

<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />
<asp:textbox id="TextBox1" runat="server" xmlns:asp="#unknown" />

<script type="text/javascript">
    function createXMLHttpRequest() {
        try {
            return new XMLHttpRequest();
        } catch (e) {
        }
        try {
            return new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
        }
        try {
            return new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {
        }
        alert("XMLHttpRequest not supported");
        return null;
    }
    function Button1_onclick() {
        var xmlHttpReq = createXMLHttpRequest();
        xmlHttpReq.open("GET", "Handler1.ashx?Value=" + document.getElementById('TextBox1').value, false);
        xmlHttpReq.send(null);
        var yourJSString = xmlHttpReq.responseText;
        alert(yourJSString);
    }
</script>

public void ProcessRequest(HttpContext context)
{
    context.Response.ContentType = "text/plain";
    string Value = context.Request.QueryString["Value"].ToString();
    if (Value == "1234")
    {
        context.Response.Output.Write("True");
    }
    else
    {
        context.Response.Output.Write("False");
    }
}
public bool IsReusable
{
    get
    {
        return false;
    }
}