if (!string.IsNullOrEmpty(emp.name) && !string.IsNullOrEmpty(this.name) && (emp.name != this.name)) {
}
[EDIT] Solution for specific case when one of the terms is null and the other is empty
if (!((emp.name == null && this.name == String.Empty) || (emp.name == String.Empty && this.name == null)) && (emp.name != this.name)) {
}
There should be a way to simplify these conditions but I do not have time for that now.
[/EDIT]