Stavba JS v utility classe, pak pres script managera nalepeni do aspx stranky pres master page a user control... Happy refactoring!

sb.Append("var wait = function () {");

sb.AppendFormat(
    "var handler = function() {0} if ({1}) {0} {1}(); window.setTimeout(wait,{2}); {3} {3}\n",
    "{", functionNamePattern, GetClientPollingCycle(),"}"
    );

sb.Append("handler();\n");
sb.Append("}\n");
sb.Append("wait();\n");