function social(){  
  if(document.getElementById('social')){
    var social=document.getElementById('soc_content');  
    var soc_href=social.getElementsByTagName('a');
      for(var i=0;i<soc_href.length;i++){
        soc_href[i].onclick=function(){
        var lft=(screen.availWidth/2)-250;//1/2 of popup width
        var tp=(screen.availHeight/2)-190;//1/2 of popup height
        window.open(this.href,'social','width=500,height=380,resizable=no,toolbar=no,menubar=no,status=no,left='+lft+',top='+tp); 
        return false;
      }
    }
  }
} 
social();