<html> <script> function add(a,b){ var n = 0; // var c = false; var c = 0; for( var i = 1; i != 0; i = i << 1) { var _a = (a & 1 ) == 1; var _b = (b & 1 ) == 1; var _n = (_a ^ _b ) ^ c; c = _a & (_b | c ) | ( _b & c ); n = n | (_n ? i : 0); a = a >> 1; b = b >> 1; } return n; } alert( add(21,32)); </script> </html>