function openwindowcenter(sourcefile,winname,winwidth,winheight){
	var baradjustment=0
	if (winwidth=="max"){
	  winwidth=screen.availWidth
    }
	if (winheight=="max"){
      baradjustment=40
      winheight=screen.availHeight-baradjustment
    }
	if(winwidth>screen.availWidth){
	  winwidth=screen.availWidth
	}
	if(winheight>screen.availHeight){
	  baradjustment=40
	  winheight=screen.availHeight-baradjustment
	}


  var aw=screen.availWidth
  var ah=screen.availHeight
  var topwin=(ah-winheight-baradjustment)/2
  var leftwin=(aw-winwidth)/2
  window.open(sourcefile,winname,"top="+topwin+",left="+leftwin+",width="+winwidth+",height="+winheight+",scrollbars=yes,resizable=yes")
}