[galaxy-dev] A job is stuck in queue

Hello, I am working with galaxy for a bioinfomatics class at Umass Amherst. I have tried doing the http://manuals.bioinformatics.ucr.edu/home/gui-ngs-analysis tutorial. I am currently on the quality control section trying to use the illumina human data set and the NGS mapping bowtie for illumina program. I enter all of the parameters and hit execute and the job sit in the history/job queue waiting to for the job to run and never runs. What can i do to fix this?? Thanks for your help ~Colin