function prepareTargetBlank(){
							   var className = 'external';
							   var as = document.getElementsByTagName('a');
							   for(i=0;i<as.length;i++){
								  var a = as[i];
								  r=new RegExp("(^| )"+className+"($| )");
								  if(r.test(a.className)){
									 a.onclick = function(){
										window.open(this.href);
										return false;
									 }
								  }
								}
							}

window.onload = prepareTargetBlank;