Shell Programming and Scripting

Hi All,
I have a requirement, in which i have to append some spaces to the variable, and then send it to another function.
I am new to the UNIX shell programming. Ultimately the length of the string should be 40 characters.
exp:
Login = "rallapalli" (length = 10)
i have to append 30 spaces to this.
it should be
Login= "rallapalli "(length =40).
Please let me know how to do this.
regards,
Rallapalli.

Code:

#!/bin/ksh
typeset -L10 a='foo'
echo "[$a]"

Code:

#!/bin/ksh

Login="rallapalli"
myVar=$(echo $Login | awk '{ printf("%-40s",$0);}' )

echo "Length is: ${#myVar}"