Yap,
Código PHP:
<script language="JavaScript">
function saltos(cual)
{
if(cual.charCodeAt(cual.length-1) == 10)
{
intro = new RegExp (String.fromCharCode(10))
texto = cual.replace(intro,"<br>")
texto = texto.replace (String.fromCharCode(13),"")
document.form1.textarea.value = texto
}
}
function saltos2(cual)
{
intro = new RegExp (String.fromCharCode(10),"g")
intro2 = new RegExp (String.fromCharCode(13),"g")
texto = cual.replace(intro,"<br>")
texto = texto.replace (intro2,"")
document.form1.textarea.value = texto
}
</script>
</head>
<body>
<form name="form1" method="post" action="">
<textarea name="textarea" cols="60" rows="6" onkeyup="saltos(this.value)" onblur="saltos2(this.value)")></textarea>
</form>
</body>
¿Ta bien?