cannot implicitly convert type 'string' to 'bool'

I get the error "cannot implicitly convert type 'string' to 'bool'" with the following code.  Can someone please tell me what I need to do?  I'm new at this!  Thanks!
private bool ValidateStatusCommit()
{
string status = ddlStatus.Text;
if (status = "I")
return true;

else

return false;
}