if-else-endif
The lines between a if-endif statement will be executed if the expression
in the if-statement is true. The expression should be surrounded by parentheses.
If an else statement is found between the if and endif the lines between else
and endif will be executed if the if-expression is false.
Example
if ( i < 10 && i > 5)
a = b + c;
endif
if ( i < 10)
a = b + c;
else
a = b - c;
endif