Faccine in un form su posizione... REVENGE

[Xinod]

totalmente crossbrowser e' impossibile

function addSml(sml) {
	var obj=document.mioform.msg;
	if (document.all) {
		obj.focus();
	  	var sel=document.selection;
	  	var rng=sel.createRange();
	  	rng.colapse;
	  	rng.text=sml;
	} else if(obj.selectionEnd){
		var lng=obj.textLength;
		var from=obj.selectionStart;
		var to=obj.selectionEnd;
		obj.value=obj.value.substring(0,from)+sml+obj.value.substring(to,lng)
	} else obj.value+=sml;
	obj.focus();
}

<form name="mioform">
<textarea name="msg"></textarea>
<input type="button" value=":)" onclick="addSml(':)')" />
</form>