concatenate varaibles var1, var2 together to var1 again

HI

i like to concatenate the two variables
var1=$line (ie 22885068900000652 B86860003OLFXXX592123320081227)
var2=$amount (ie 123456)

i want to club together both the above varaible var1 & var2 and assign back to var1

right now i am doing like this but it is not working.
var1=`echo $var1" "$var2`

result should be
$var1
22885068900000652 B86860003OLFXXX592123320081227 123456

Thanks

var1="22885068900000652 B86860003OLFXXX592123320081227"
var2="123456"
var1="$var1 $var2"
echo $var1