javascript - Memory leak in Firefox with jQuery, AJAX, and HTML5 canvas -

i'm polling server using jquery's ajax function , using data update canvas. poll server once each second (this not done using setinterval(), in case you're wondering... did hear source of these issues. canvas animated, , keep track of frame rate. use data figure out when second has elapsed). isn't issue in chrome, in firefox , maxthon cloud (and much lesser degree opera), performance gradually grows worse , worse. think it's ajax calls, , have no idea how fix issue. here "callserver()" function, if that's of use. thanks!

function callserver(action, json) {     if(!json)     {         $.ajax({             type: 'post',             url: 'okey.php.',             data: 'action=' + action,             cache: false,             success: function(data)             {                 switch(action)                 {                     case 'ptv':                         tilesvalue = data;                         break;                     case 'ptc':                         tilescolor = data;                         break;                     case 'tid':                         //alert(data);                         thisplayerid = data;                         break;                     case 'pti':                         playerturninfo = data;                         //alert(data);                         break;                     case 'gs':                         gamestatus = data;                         break;                     case 'steal':                         alert(data);                         break;                     case 'draw':                         alert(data);                         break;                     case 'testing':                         alert(data);                         break;                 }             }         });     }     else if(json)     {         $.ajax({             type: 'post',             url: 'okey.php.',             data: 'action=' + action,             datatype: 'json',             cache: false,             success: function(data)             {                 switch(action)                 {                     case 'ptv':                         tilesvalue = data;                         break;                     case 'ptc':                         tilescolor = data;                         //alert(tilescolor.length);                         break;                     case 'pn':                         playernames = data;                         break;                     case 'pid':                         playerids = data;                         break;                     case 'pts':                         //alert("excellent");                         turnstatuses = data;                         break;                     case 'ti':                         tileindeces = data;                         //alert(tileindeces.length)                         break;                     case 'dis':                         //alert(parseint(data[3]));                         discarded = data;                         //alert(parseint(discarded[3]));                         break;                 }             }         });     } } 

update: not frequency of calls causing issue.