On Load value for URL field?

On Load value for URL field?

I think I've figured out how to populate Link Name in the URL field using On Load as follows:

input.project_docs = "<a href=''>Project Docs</a>";

However, is it possible to disable *only* the Link Name field On Load, so that the user can put whatever URL they want in but the Link Name will always be "Project Docs"?

Thanks!