function launch(varURL, varName, varFeatures) {
			  window.open(varURL,varName,varFeatures);
			}
			
function launchCentered (varURL, varName, varWidth, varHeight, varFeatures) {
  if (!varName) varName = '';
  if (!varFeatures) 
		varFeatures = '';
  else
    varFeatures = ',' + varFeatures;
			    
  var x = Math.round((screen.availWidth - varWidth) / 2);
  var y = Math.round((screen.availHeight - varHeight) / 2);
			  
  varFeatures = 'left=' + x + ',top=' + y + ',width=' + varWidth + ',height=' + varHeight + varFeatures;
  window.open(varURL,varName,varFeatures);
}