I want to submit this form through PHP. with validation for required field and validation for phone number and email field also

<form action="" method="" id="get-protected">
<div class="row requiredRow">
    <label for="txt_FirstName">
        First Name</label>
    <input id="txt_FirstName" type="text" class="required" title="First Name. This is a required field" />
</div>
<div class="row">
    <label for="txt_LastName">
        Last Name</label>
    <input id="txt_LastName" type="text" title="First Name. This is a required field" />
</div>
<div class="row">
    <label for="txt_Phone">
        Phone</label>
    <input id="txt_Phone" type="text" title="First Name. This is a required field" />
</div>
<div class="row requiredRow">
    <label for="txt_Email">
        Email</label>
    <input id="txt_Email" type="text" class="required" title="Email. This is a required field" />
</div>
<div class="row">
    <input type="submit" value="" class="button" />
</div>
</form>