programming

Question

i wrote a code to enable users add item to listBox clears the items from the textBox1 and ComboBox1.But wen i real click without inputing any thing,the textBox1 gives space in the listBox and the ComboBox1 add the previous item that was selected when not as been selected.

   How do i solve this problem and how to make the user no when he or she as not inputed any thing.

}

if (ComboBox1->Empty & textBox1->Empty==true)

Message->Show("Error");

}

but am getting errors