子程序 请教

007.for(57): error #6303: The assignment operation or the binary expression operation is invalid for the data types of the two operands. [MAT1]
if (cmname(1:2) .eq. MAT1) then
---------------------------^
007.for(59): error #6303: The assignment operation or the binary expression operation is invalid for the data types of the two operands. [MAT2]
else if (cmname(1:2) .eq. MAT2) then
--------------------------------^
007.for(130): error #6303: The assignment operation or the binary expression operation is invalid for the data types of the two operands. [MAT1]
if (cmname(1:2) .eq. MAT1) then
---------------------------^
007.for(137): error #6303: The assignment operation or the binary expression operation is invalid for the data types of the two operands. [MAT2]
else if (cmname(1:2) .eq. MAT2) then
请问这需要怎么修改，哪位仁兄能回答下吗，谢过！！！