st: Destring command

[Jumin Kim <kim.jumin@gmail.com>]

I'm trying to destring a string variable by using the following command:
    destring r05_, gen (immig_spec)

But, I get the following message:
    r05_ contains non-numeric characters; no generate

How do I get around this.  Thank you.
jumin

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/