if expr1 then statement1;

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if expr1 then statement1 else statement2;

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if expr1 then statement1 else if expr2 then statement2;

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If expr1 then 
Begin
Statement1;
Statement2;
�c
End
Else
Begin
OtherStatement1;
OtherStatement2;
�c
End;

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Remember to use parenthesis ( ) , to enclose boolean expressions when using logical operator.
e.g.  (a<2) and (a<7)