Hola haber si te sirve esto:
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
<script language="JavaScript" type="text/javascript">
function escoge(){
with (document.form1){
resultado.value=select1.value;
alert("Has escogido " + select1.value)
}
}
</script>
<form name="form1" method="post" action="">
<select name="select1">
<option value="5">hola</option>
<option value="10">hola2</option>
</select>
<input type="submit" name="Submit" value="checar" onClick="escoge()">
<input type="text" name="resultado">
<img src="imagenes23/acrobat.gif" width="36" height="34" onClick="escoge()">
</form>
</body>
</html>