if expression syntax error

Shell Programming and Scripting
1 
 
#! /bin/csh
set umr=UMR
foreach  i ( `ls`)
   set file_nm=$i
   set bh_nm=`echo $file_nm | cut -d"_" -f2`

      if($bh_nm !=$umr) then
      {
       set bh_ext=`echo $file_nm | cut -d"_" -f4`
       set bh_num_nm="$bh_nm $bh_ext a .txt"
       mv $file_nm  $bh_num_nm
      }
      else
      if ($bh_nm ==$umr) then
      {
         set um_ext=`echo $file_nm | cut -d"_" -f5`
               if ($um_ext=="1.txt") then set um_ext_new=1
               else
               if ($um_ext=="2.txt") then set um_ext_new=2
               endif
         set umr_bh=`echo $file_nm | cut -d"_" -f3`
         set umr_nm= "$umr_bh $um_ext_new b .txt"
         mv $file_nm  $umr_nm
      }
      endif
end

why i always got the error:

Code:
if: Expression syntax error?

Thanks so lot.

2

Double post, continued here, thread closed.