PHP JS submit button

Hi guys i need your help so i make a submit button with js but i have a register and a login on the same one page file so when i run the register goes fine but if i use the login , the login uses the register files for example.

<form name="as" method="POST" action="loginpro.php">
    Username: <input type="text" name="username" /><br /><br />
    Password: <input type="password" name="password" /><br /><br />
    <input style="font-size: 17px" type=button onClick="submitform()" value="Submit"/>
 </form>

This is the code that i'm using to make the login form and as you can see i call a file with the name loginpro.php where i have the php settings to ask the db the files that i need but when i execute it he is calling regpro.php that is the file that im using for register take a look.

<form name="register" method="POST" action="regpro.php">
    Username: <input type="text" name="username" /><br /><br />
    Email: <input type="text" name="Email" /><br /><br />
    First Name: <input type="text" name="fname" /><br /><br />
    Last Name: <input type="text" name="lname" /><br /><br />
    Password: <input type="password" name="password" /><br /><br />
    <input style="font-size: 11px" type=button onClick="submitform()" value="Submit"/>
</form> 

Sorry if my english is bad i tried my best to make it clear. Thanks to everybody that helps.