Calling External URL in new Tab

When we calling any external URL from OAF page, we need to add destination URI as below. So URL will open in new tab with same browser.

javascript:var a = window.open(‘{$Weburl}’, ‘a’,’scrollbars=yes,height=700,width=1100,status=yes,toolbar=yes,menubar=yes,location=yes,resizable=yes’); a.focus();