ZaValera,
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link REL=STYLESHEET TYPE="text/css" HREF="main.css">
</head>
<body>
<form id="loadForm" class="container" method="post" enctype="multipart/form-data" action="upload.php" >
<input type="text" value="Загрузить"/>
<input id="submit" style="display:none" type="submit" name="upload" value="Загрузить"/>
</form>
</body>
<input type="button"value="Загрузить" onclick="document.getElementById('submit').click()"/>
</html>