Check Against Last Click On Command Button

I'm working with 2 different sheets, sheet1 and sheet2.

I'll type in entry 1 to 4. 2 comboboxes, 2 cell values. then click on the command button1.

i'll pass over the values to sheet2 like this:
array(comboBox1.value, range("a2").value, comboBox2.value, range("a4").value

I was asked to check against the last time the user click on the command button.
if combobox1.value, range("a2").value, comBoBox2.value, range("a4").value MATCHES exactly the last entry in sheet2, it'll give a popup Box before it continues.