grails web flow doesn't work

Question

start{
          on('next'){.... }.to "connectusers" 
     }
  connectusers { 
                   on("next").to "congrats" 
     } 
  congrats()

this flow doesn't work but if I run each step alone it's ok Work:

start{
        on('next'){.... }.to "connectusers"
      }
 connectusers {}

also work...

 start{
        on('next'){.... }.to "congrats" 
      }
 congrats()

where I did wrong?