the compilation stops after 25 errors which most of them are like:
"
tpem15.f:61.9:

        rf.refmsl(1,1)=idu2
        1
Error: Unclassifiable statement at (1)
"
as you can sea my statement doesn't start before the 7th column.

Can someone help me?

Is there a period in your variable name?  The Fortran 77 standard only allows for alphanumeric characters in variable names.  If your are attempting to use a construct similar to C "struct," there is a good chance that the construct was an extension to the particular legacy compiler.  There is a good chance GNU Fortran does not support this construct directly.

Some fairly basic things that I'm sure you'll have checked already...
Does any of the code stray beyond the 80th character in the line?
Do you have any comments tagged onto the ends of lines, with the "!" delimeter missing?
Have you used any variable names that were permitted on the other compiler but are not permitted in ANSI Fortran (eg names with decimals in the name, like REAL*4 rf.refms(20, 20))?

If no-one knows the answer, can you upload a small specimen program that gives the error during compiling, so that people can search for the problem beyond the immediate vicinity of where it occurs?
---
John

the compilation stops after 25 errors which most of them are like:
"
tpem15.f:61.9:

        rf.refmsl(1,1)=idu2
        1
Error: Unclassifiable statement at (1)
"
as you can sea my statement doesn't start before the 7th column.

Can someone help me?