function Quotes(btn) {
     if (btn.name == "Lincoln") { // here we're checking the Button's NAME
          alert("Four score and seven years ago ...");
     }
     else if (btn.value == "JFK") { // here we're checking the Button's VALUE
          alert("Ask not what your country can do for you ...");
     }
     else {
          alert("I am not a crook ...");
     }
}

</SCRIPT>

<FORM>
     <INPUT TYPE="BUTTON" VALUE="Lincoln" NAME="Lincoln" onClick="Quotes(this);">
     <INPUT TYPE="BUTTON" VALUE="JFK" NAME="Kennedy" onClick="Quotes(this);">
     <INPUT TYPE="BUTTON" VALUE="Nixon" NAME="Nixon" onClick="Quotes(this);">
</FORM>