I don't know much about PHP coding. I have this contact form:
<div id="content">
   <h1> Contact me </h1>
    <form action=" " method="post"  autocomplete="on">
        <p> <label for="username" class="iconic user" > Name <span class="required">*</span></label> <input type="text" name="username" id="username"  required="required" placeholder="Hi friend, how may I call you ?"  /> </p>
        <p> <label for="usermail" class="iconic mail-alt"> E-mail address <span class="required">*</span></label> <input type="email" name="usermail" id="usermail" placeholder="I promise I hate spam as much as you do" required="required"  /> </p>
        <p> <label for="usersite" class="iconic link"> Website </label> <input type="url" name="usersite" id="usersite"  placeholder="eg: http://www.miste.com" /> </p>
        <p> <label for="subject" class="iconic quote-alt"> Subject </label> <input type="text" name="subject" id="subject"  placeholder="What would you like to talk about?" /> </p>
        <p> <label for="message" class="iconic comment"> Message  <span class="required">*</span></label> <textarea placeholder="Don't be shy, live me a friendly message and I'll answer as soon as possible "  required="required" ></textarea> </p>
        <p class="indication"> All fields with a <span class="required">*</span> are required</p>
        <input type="submit" value=" ★  Send the mail !" />     
    </form>     
</div> 
I want the " Send the mail !" button to send the details directly to my email.
What files should I make? The contact form file is already a PHP file but I don't know what to add !
Sorry for my bad English, Let me know if you didn't understand my Question!