var name = $get("txtName").value;
PageMethods.GetCurrentDate(name, OnSuccess, OnFailure);
}
function OnSuccess(result) {
    if (result) {
        alert(result);
    }
}
function OnFailure(error) {
}
here GetCurrentDate id codebehind method name, in this method there are 3 parameters,how many parameters we can define here,how we can call methos in which grid view bind on given id through this method.
        var obj1 = {};
        obj1.mangerid = $.trim($("[id*=txtmanagerid]").val());
        obj1.clientid = $.trim($("[id*=txtclientid]").val());
 
        $.ajax({
            type: "POST",
            url: "sqlwebmethod1.aspx/GetChat",
            data: JSON.stringify(obj1),
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: OnSuccess,
            failure: OnError,
 
            error: OnError,
 
        });
        return false;
    });
 
 
    function OnSuccess(response) {
        var xmlDoc = $.parseXML(response.d);
        var xml = $(xmlDoc);
        var customers = xml.find("Table");
        var row = $("[id*=grdchat] tr:last-child").clone(true);
        $("[id*=grdchat] tr").not($("[id*=grdchat] tr:first-child")).remove();
        $.each(customers, function () {
            var customer = $(this);
            $("td", row).eq(0).html($(this).find("message").text());
            //$("td", row).eq(1).html($(this).find("ContactName").text());
            //$("td", row).eq(2).html($(this).find("City").text());
            $("[id*=grdchat]").append(row);
            row = $("[id*=grdchat] tr:last-child").clone(true);
        });
    }
 
    //i changed this code to
        var m = document.getElementById("<%=txtmanagerid.ClientID%>").value;
        var n= document.getElementById("<%=txtclientid.ClientID%>").value;
        $.ajax({
            type: "POST",
            url: "sqlwebmethod1.aspx/GetChat",
            data: '{managerid: "' + m + '",clientid:"'+n+'"}',
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: OnSuccess,
            failure: OnError,
            
            error: OnError,
             
        });
        return false;
    });
     
 
    function OnSuccess(response) {
        var xmlDoc = $.parseXML(response.d);
        var xml = $(xmlDoc);
        var customers = xml.find("Table");
        var row = $("[id*=grdchat] tr:last-child").clone(true);
        $("[id*=grdchat] tr").not($("[id*=grdchat] tr:first-child")).remove();
        $.each(customers, function () {
            var customer = $(this);
            $("td", row).eq(0).html($(this).find("message").text());
            //$("td", row).eq(1).html($(this).find("ContactName").text());
            //$("td", row).eq(2).html($(this).find("City").text());
            $("[id*=grdchat]").append(row);
            row = $("[id*=grdchat] tr:last-child").clone(true);
        });
    }
it's working but 1 have 2 script, showing data of last script only