little help please

register.html
<body>
<form action="register.php" method="post" enctype="multipart/form-data" name="form1" id="form1">
<table width="410" border="0" align="center" bordercolor="#99FFFF">
<tr align="center" valign="middle">
<td colspan="3"> <span class="style1">User Registration</span> </td>
</tr>
<tr>
<td width="156" align="left"><div align="right" class="style4">UserName</div></td>
<td width="22">:</td>
<td width="218"><div align="left">
<input name="username" type="text" name="username" />
</div></td>
</tr>
<tr>
<td><div align="right" class="style4">Password</div></td>
<td>:</td>
<td><label>
<div align="left">
<input name="passwrod" type="password" name="passwrod" />
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">E mail</div></td>
<td>:</td>
<td><label>
<div align="left">
<input type="text" name="email" />
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">Address</div></td>
<td>:</td>
<td><label>
<div align="left">
<textarea name="address"></textarea>
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">Country</div></td>
<td>:</td>
<td><label>
<div align="left">
<select name="country">
<option>india</option>
<option>usa</option>
<option>pak</option>
<option>england</option>
<option>aus</option>
<option>newzeland</option>
<option>rsa</option>
<option>srilanka</option>
<option>west indies</option>
</select>
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">City/Area</div></td>
<td>:</td>
<td><label>
<div align="left">
<select name="area" size="1" multiple="multiple" id="area">
</select>
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">Pin Code </div></td>
<td>:</td>
<td><label>
<div align="left">
<input name="pin" type="text" id="pin" />
</div>
</label></td>
</tr>
<tr>
<td><div align="right" class="style4">Phone Number </div></td>
<td>:</td>
<td><label>
<div align="left">
<input name="counrtycode" type="text" id="counrtycode" size="3" maxlength="3" />
<input name="phoneno" type="text" id="phoneno" />
</div>
</label></td>
</tr>
<tr>
<td><div align="left" class="style4">
<div align="right">Upload Your Photo </div>
</div></td>
<td><div align="left">:</div></td>
<td><label>

<div align="left">
<input type="file" name="file" />
</div>
</label></td>
</tr>
<tr>
<td colspan="3"><label>
<div align="center">
<input type="submit" name="Submit" value="Submit" />
</div>
</label></td>
</tr>
</table>
</form>
</body>

register.php

<?php
$con=mysql_connect("localhost","root","");
mysql_select_db("user",$con);
$username = $_post[username];
$password = $_post[password];
$email = $_post;
$add = $_post[address];
$contry=$_post[country];
$area=$_post[area];
$pin=$_post[pin];
$countrycode=$_post[countrycode];
$phoneno=$_post[phoneno];
$file=$_post[file];
$qry="INSERT INTO user1 (username,password,email,address,country,area,pincode,countrycode,phoneno,file) VALUES ('$username','$password','$email','$add','$contry','$area','$pin','$countrycode','$phoneno','$file')";
mysql_query($qry,$con);
mysql_close($con);
?>
the following errors occured.how to fix these bugs.
Notice: Use of undefined constant username - assumed 'username' in c:\easyphp1-8\www\register.php on line 10

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 10

Notice: Use of undefined constant password - assumed 'password' in c:\easyphp1-8\www\register.php on line 11

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 11

Notice: Use of undefined constant email - assumed 'email' in c:\easyphp1-8\www\register.php on line 12

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 12

Notice: Use of undefined constant address - assumed 'address' in c:\easyphp1-8\www\register.php on line 13

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 13

Notice: Use of undefined constant country - assumed 'country' in c:\easyphp1-8\www\register.php on line 14

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 14

Notice: Use of undefined constant area - assumed 'area' in c:\easyphp1-8\www\register.php on line 15

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 15

Notice: Use of undefined constant pin - assumed 'pin' in c:\easyphp1-8\www\register.php on line 16

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 16

Notice: Use of undefined constant countrycode - assumed 'countrycode' in c:\easyphp1-8\www\register.php on line 17

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 17

Notice: Use of undefined constant phoneno - assumed 'phoneno' in c:\easyphp1-8\www\register.php on line 18

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 18

Notice: Use of undefined constant file - assumed 'file' in c:\easyphp1-8\www\register.php on line 19

Notice: Undefined variable: _post in c:\easyphp1-8\www\register.php on line 19

 

$_post[username]; -> $_POST['username']; use this format you are using wrong format