How to use if else condition

Hi friends,
How can i write if else condition for bewlow queries. I wrote like as below but, i am getting errors.
if(r.version >1)
begin
select b.bidid, r.BidrefName,b.StartDate,b.EndDate, r.version from dbo.tblBid b inner join dbo.tblBidref r on b.BidID= r.BidID where DealID=89914275 and Version=2
end
else
begin
select b.bidid, b.Description, b.StartDate,b.EndDate,r.version from dbo.tblBid b inner join dbo.tblBidref r on b.BidID= r.BidID where DealID=89914275 and Version=1
end

error: 
Msg 4104, Level 16, State 1, Line 1 The multi-part identifier "r.version" could not be bound.
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