<input type="text" value="" id="inp1" />
<input type="text" value="" id="inp2" />

<input type="button" onclick="add('Текст')" value="Добавить" id="add" />
<script>
function add(text){
var a=document,inp1=a.getElementById('inp1'),inp2=a.getElementById('inp2');
(!text)?inp1.value='':inp1.value=text;
(!text)?inp2.value='':inp2.value=text;}
</script>

<script>
function add(text){
var a=document,inp1=a.getElementById('inp1'),inp2=a.getElementById('inp2');
inp1.value+=text;
inp2.value+=text;}
</script>

<script>function add(){alert(true)};

document.getElementById('nwF7').onclick=function(){add();return false}</script>

<script>
function add(){alert(true)};

$('#nwF7').click(function(){add()})
</script>

$('#nwF7').click(add);