PHP_WORDWRAP in javascript
function wordwrap( str, width, brk, cut ) {
brk = brk || '\n';
width = width || 75;
cut = cut || false;
if (!str) { return str; }
var regex = '.{1,' +width+ '}(\\s|$)' + (cut ? '|.{' +width+ '}|.+$' : '|\\S+?(\\s|$)');
return str.match( new RegExp(regex, 'g') ).join( brk );
}