Need Help to create select field on Add Listing Form

Dear admin,

I am trying to add an select field on business listing form. I have successfully added the select field into the from. I have marked that select field as a required. But if when I submit the form without selecting any option from that select field it doesn’t show error. I added this line on option value field
{optgroup}Click here to select,Business Directory,From Friend,Facebook,Twitter,Linkedin,Instagram,Search Engine{/optgroup}
please take a look and tell me what is wrong with my writing. Waiting for your response.
site link: http://listingbiz.com

thanks