<!DOCTYPE html> <html> <head> <script> function repeatChar(s, n) { while (s.length < n) s += s; return s.substr(0, n); } function boom() { document.documentElement.contentEditable = "true"; document.execCommand("inserthtml", false, "<button><\/button>"); document.execCommand("inserthtml", false, repeatChar("i", 34646)); document.execCommand("contentReadOnly", false, null); document.execCommand("removeformat", false, null); document.execCommand("hilitecolor", false, "red"); document.execCommand("inserthtml", false, "a"); document.execCommand("delete", false, null); } </script> </head> <body onload="boom();"></body> </html>