$(document).ready(function() 
{
   // Notice the use of the each method to gain access to each element individually
   $('img.imgtip').each(function()
   {
      var content = '';
      content += $(this).attr('alt');
      
      // Setup the tooltip with the content
      $(this).qtip(
      {
         content: content,
         position: {
            corner: {
               tooltip: 'leftBottom',
               target: 'rightBottom'
            }
         },
         style: {
            tip: true, // Give it a speech bubble tip with automatic corner detection
            name: 'dark'
         }
      });
   });
});