<form action="gogogo.php" method="post" enctype="multipart/form-data">
<label class="filebutton">
Upload
<span><input type="file" id="myfile" name="myfile" onchange="this.form.submit();"></span>
</label>

label.filebutton {
width:300px;
height: 100px;
overflow:hidden;
position:relative;
background-color:#FF9933;
}

label span input {
z-index: 999;
line-height: 0;
font-size: 50px;
position: absolute;
top: -2px;
left: -700px;
opacity: 0;
filter: alpha(opacity = 0);
-ms-filter: "alpha(opacity=0)";
cursor: pointer;
_cursor: hand;
margin: 0;
padding:0;
width: 50px;
}