ClientScript Not Working Properly On Class C#

I want to deploy a script on C# which usually uses methods like: ClientScript.RegisterStartupScript(GetType(), 'script', 'Details('' + hdnId.Value + '');', true); However I wanted

Solution 1:

I have this function, and it always works, try it

public static void callJavascriptFunction(string strScript)
    {

            if (HttpContext.Current == null && HttpContext.Current.Handler is Page) { return; }

            Page currentPage = (Page)HttpContext.Current.Handler;
            ScriptManager.RegisterStartupScript(currentPage,
                                                currentPage.GetType(),
                                                "Funct",
                                                strScript,
                                                true);
    }