Need to combine 3 column

Hi experts,

I am new to crystal report.I have four column report in which for certain condition I need to combine three columns.

I used following formula I get result but value print like double.

Please find attachment.

if {column3}="-" then

stringVar x := {column2};

stringVar y := {column3};

y:=''";

x:= x & ' ' & y

Thanks in advance.