rem: viewPicker.selectedItem = document.getElementById(id); viewChange(viewPicker, viewPicker.value); 
add: if (viewPicker) { viewPicker.selectedItem = document.getElementById(id); viewChange(viewPicker, viewPicker.value); } 
context: function ViewMessagesBy(id){  var viewPicker = document.getElementById('viewPicker');  viewPicker.selectedItem = document.getElementById(id);  viewChange(viewPicker, viewPicker.value);}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/ec32b156669255b816d1c92245c208d317777b50/mailWindowOverlay.js/clean/mail/base/content/mailWindowOverlay.js