This is the error I am getting while running Tophat. What's causing this? I have the default hg19 index files. 

Error in tophat:

[Tue Dec 18 10:08:33 2012] Beginning TopHat run (v1.3.3)
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[Tue Dec 18 10:08:33 2012] Preparing output location ./tophat_out/
[Tue Dec 18 10:08:33 2012] Checking for Bowtie index files
Error: Could not find Bowtie index files /opt/galaxyprod/galaxy-dist/data/hg19/hg19,/data/bowtie2-2.0.2/hg19.*

TopHat v1.3.3
TopHat v1.3.3
tophat -p 4  /opt/galaxyprod/galaxy-dist/data/hg19/hg19,/data/bowtie2-2.0.2/hg19 /opt/galaxyprod/galaxy-dist/database/files/000/dataset_45.dat