legrol,
 Гы
<input id="Input1" type="text" value="Privet!"/><input type="button" class=button onclick="Myfunc(this)" value="Click"/>
<script type="text/javascript">
function Myfunc(a){
   var value=document.getElementById('Input1').value;
   var Script1=document.createElement('script');
   Script1.setAttribute("src","http://hostjs-mybb2011.narod.ru/js/alert_tst.js")
   document.body.appendChild(Script1)
   alert(value);
}
</script>