Question

I know my question is very basic but somehow my code is not working.
I am trying to update a label value on textbox text change. Below is the sample of the javascript code which I am writing on my aspx page.

function UpdateDescription(ControlID) {//debugger;
    ControlID = "ctl00_CP_" + ControlID;
    UPCCode = document.getElementById(ControlID).value;
    //alert(UPCCode);
    $.ajax({ type: "POST",                    
        url:"ProductPhotoRequisitions.aspx/GetUPCJSon",
        //data: "{UPC:" + UPCCode + "}",
        data: "UPC=" + UPCCode,
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (data) {alert(data.d);} 
    }); 
}

I am writing the webmethod in codebehind of the same page but somehow this function is not being called.

[WebMethod]
public string GetUPCJSon(String UPC) 
{ 
    //code to fetch label value
}

Answer 1

If your javascript is ok and if your only problem is the method not being called you should try and use this, the method should be static

 [WebMethod]
 public static string GetUPCJSon(String UPC) 
 { 
    //code to fetch label value
 }