var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	function decode64(input) {
		var output = "";
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;
		// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
		do {
		  enc1 = keyStr.indexOf(input.charAt(i++));
		  enc2 = keyStr.indexOf(input.charAt(i++));
		  enc3 = keyStr.indexOf(input.charAt(i++));
		  enc4 = keyStr.indexOf(input.charAt(i++));
		  chr1 = (enc1 << 2) | (enc2 >> 4);
		  chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		  chr3 = ((enc3 & 3) << 6) | enc4;
		  output = output + String.fromCharCode(chr1);
		  if (enc3 != 64) {
			 output = output + String.fromCharCode(chr2);
		  }
		  if (enc4 != 64) {
			 output = output + String.fromCharCode(chr3);
		  }
		} while (i < input.length);
		return output;
	}