Fortran - GOTO

Executable GOTO statements:

  GOTO snr1    - ordinary GOTO statement (jumps to the statement with

                 number snr1)



? GOTO (snr1, snr2, snr3), integer_expression - conditional GOTO statement. If the integer expression is 1, 2 or 3, execution jumps to statement number snr1, snr2 or snr3 (an arbitrary number of statement numbers snr are permitted).



??GOTO statement_number_variable, (snr1, snr2, snr3)

               - an assigned GOTO statement, jumps to the statement

                 number that equals the statement

                 number variable (an arbitrary  number of

                 statement numbers snr are permitted).



??GOTO statement_number_variable

               - this is an assigned ordinary GOTO statement, it is a

                 combination of the first one, GOTO snr1, and

                 previous one, GOTO statement_number_variable without

                 a list of permitted alternatives.



??ASSIGN statement_number TO statement_number_variable

               - statement number variables can not be assigned with

                 an ordinary assignment of the type (integer

                 variable = integer expression), it has to be

                 done with the ASSIGN statement.  The statement

                 number variable can then be used for an assigned

                 GOTO statement and in the ordinary GOTO statement

                 and also in connection with FORMAT.



? IF (numerical_expression) snr1, snr2, snr3

               - arithmetical IF-statement, jumps to statement number

                 snr1 if the expression is negative,

                 snr2 if the expression is zero,

                 snr3 if the expression is positive

refer: http://www.nsc.liu.se/~boein/f77to90/a2.html#section4