[Viper]

<form method="post">
Input text: <input type="text" onkeyup="ajaxFunction1();" name="in1" id="in1">
ajax result: <input type="text" name="out1" id="out1">
</form>

$(document).ready(function(){
	function ajaxFunction1(){
	var data = $("#in1").val();
	$.ajax({
   		type: "POST",
   		url: "test.php",
   		data: "intext="+data,
   		success: function(msg){
     			$("#out1").text(msg);
   		}
 	});
	}
});

а так ?