si che si puo!
Codice PHP:
<html>
<head>
<title>Documento senza titolo</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" type="text/JavaScript">
<!--
function MM_findObj(n, d) { //v4.01
var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
if(!x && d.getElementById) x=d.getElementById(n); return x;
}
function MM_setTextOfTextfield(objName,x,newText) { //v3.0
var obj = MM_findObj(objName); if (obj) obj.value = newText;
}
//-->
</script>
</head>
<body>
<label></label>
<form name="form1" method="post" action="">
<textarea name="textarea" id="pippo"> </textarea>
<input name="Submit" type="button" onClick="MM_setTextOfTextfield('pippo','','prova')" value="Pulsante">
</form>
<label></label>
</body>
</html>
ciao medo