A few restrictions

To make things simpler some of the files names are expected to follow certain patterns:

• XMM source lists may have user specified file names. If the file is an ASCII table (.txt file) the first three lines should describe its format (example in documentation for dbcreate_xmm_txt routine). It can also be an EML FITS file. The only required information is RA, Dec and flux or counts for the `52' band.
• The names of XMM images should be of the form n**-img.fits where `**' is `25', `52', `24', `41' or`57'. XID work can proceed in the absence of any images.
• WFC images and unmerged source lists sould have a name of the form rrunno.fit and rrunno_*_cat.fit where `*' is `1', `2', `3' or `4' respectively. It is assumed that if an image is present all four coresponding source lists are and vice--cersa.
• Merged WFC source lists should have a name of the form name_*.mer where `*' is `1', `2', `3' or `4'. It is assumed that if one list is present all four are.
• The name of CIRSI source lists and images is user--specified.
• APMCAT source lists and DSS images should have a name of the form apmcat-****-field.fct and dss_stsci_****-***.fits respectively, where `****' is `ukst' or `poss1' or `poss2' and `***' is `red' or `blue'.