asp.net - registerclientscriptblock on javascript callback -

i have javascript function checks lat long , runs on page load. calls page method lat long. in page method, use registerclientscriptblock set bunch of variables, , return string of javascript display map uses variables. map loads, error variables expecting undefined.

<script type="text/javascript">            function check() {                    if (navigator.geolocation) {             var panelprog = $get('progress');             panelprog.style.display = '';             var panelprog = $get('map');             panelprog.style.display = 'none';                           navigator.geolocation.getcurrentposition(function (position) {                                    // access them accordingly                 pagemethods.setsession(position.coords.latitude, position.coords.longitude, callback);             });         }     }     function callback(result) {          eval(result);     } </script>   [webmethod] public static string setsession(string latval, string longval) {     //does work, calls registerclientscriptblock set bunch of array variables    //var lats = new array(); var longs = new array(); etc...     return "displaymap(" + latval + "," + longval + ");"; } 

it's not gonna work because pagemethod not perform page cycle. mean page not postback , script not rendered.

you can work around returning script.

[webmethod] public static string setsession(string latval, string longval) {     var js = "lats = new array(); var longs = new array();"; //etc...     js += "displaymap(" + latval + "," + longval + ");";     return js; }