<script>
function drawMes(pole,text)
{
document.forms[0].pole.value = document.forms[0].pole.value + text;
document.forms[0].pole.focus();
}
var strUMenyaFocus="";
for(i=0;i<document.forms['0'].length;i++){
if( document.forms['0'].elements[i].name==strUMenyaFocus)
{
drawMes(document.forms['0'].elements[i],text);
}
}
</script>
<a href="javascript:drawMes(text);">Вставить слово "text"</a>
<form name="0">
<input type=text name=name1 onfocus="strUMenyaFocus=this.name">
<input type=text name=name2 onfocus="strUMenyaFocus=this.name">
<input type=text name=name3 onfocus="strUMenyaFocus=this.name">
</form>