var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.fillStyle="#FF0000";
ctx.fillRect(0,0,150,75);
//var canvas = c.toDataURL()
var blob = c.msToBlob()
navigator.msSaveBlob(blob, 'a.png')
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.fillStyle="#FF0000";
ctx.fillRect(0,0,150,75);
//var canvas = c.toDataURL()
var blob = c.msToBlob()
navigator.msSaveBlob(blob, 'a.png')