ASP.NET C# RegisterClientScriptBlock

I want to convert this Javascript on Client page to the Code Behind C# page .....


string strCsharp = "CsharpPage"; //// Only this variable is being passed from Code Behind.. It has to be written on server side when a button is clicked....
            <script language="javascript">
            
            function GetPage()
                  {
                               
                         var frm = document.forms[0];
                         frm.HiddenStudent.value = 'yes';  // Hiddenvariable
                         frm.HiddenGoToPage.value = 'Admin.aspx';
                         frm.HiddenCSHARPVALUE.value = strCsharp;  //value being passed from csharp code behind
                         frm.document.action = 'GotoASPPage.asp';
                         frm.document.submit();
                     
          }