Null values giving error in Computed columns

[Sandy381]

Hi,

I'm trying to generate computed column to one of my columns in table.

But when i try to generate a computed column out of string column it generates the below error.

How can i Overcome this error?

[fbaligand]

How many columns do you have?
If you have 4 columns, last column is col3, because col index is 0-based