changepassworduser.php

<?php
include("header.php");
if($_SESSION[sessionid] == $_POST[sessionid])
{
	if(isset($_POST[submit]))
	{
		$ectopass=md5($_POST[oldpassword]);
		$ectnpass=md5($_POST[newpassword]);
		$sql="UPDATE user SET password=$ectnpass WHERE password=$ectopass AND user_id=$_SESSION[user_id] ";
		$qsql = mysqli_query($con,$sql);
		echo mysqli_error($con);
		if(mysqli_affected_rows($con) == 1)
		{
			echo "<SCRIPT>alert(Password updated successfully.);</SCRIPT>";
			echo "<script>window.location=dashboard.php;</script>";
		}
		else
		{
			echo "<SCRIPT>alert(Failed to update password...);</SCRIPT>";			
		}
	}
}
$_SESSION[sessionid] = rand();
?>

  <section id="contentSection">
    <div class="row">
      <div class="col-lg-8 col-md-8 col-sm-8">
        <div class="left_content">
          <div class="contact_area">
            <h2>Change Password</h2>
            <p>You can change password here.</p>
             <form action="" class="contact_form" method="post" name="frmchangepassworduser" onsubmit="return validateform()">
             <input  type="hidden" name="sessionid" value="<?php echo $_SESSION[sessionid]; ?>" >
             Old Password:
             <input name="oldpassword" class="form-control" type="password" placeholder="Old Password *">
             <span id="idoldpassword"></span>
           	 <br>
             New Password:
             <input name="newpassword" class="form-control" type="password" placeholder="New Password *">
             <span id="idnewpassword"></span>
          	 <br>
             Confirm Password:
             <input name="confirmpassword" class="form-control" type="password" placeholder="Confirm Password *">
             <span id="idconfirmpassword"></span>
          	 <br>
             <input name="submit" type="submit" value="Submit">
             </form>
          </div>
        </div>
      </div>
     
    </div>
  </section>
 <?php
 include("footer.php")
 ?>
  <script type="application/javascript">
 function validateform()
 {
	 var validatecondtion = 0;
	     
	 document.getElementById("idoldpassword").innerHTML ="";
	 document.getElementById("idnewpassword").innerHTML ="";
	 document.getElementById("idconfirmpassword").innerHTML ="";
	  
	 if(document.frmchangepassworduser.oldpassword.value.length < 8)
	 {
		 document.getElementById("idoldpassword").innerHTML ="<font color=red>Password must contain at least 8 characters..</font>";
		 validatecondtion=1;
	 }
	 if(document.frmchangepassworduser.oldpassword.value=="")
	 {
		 document.getElementById("idoldpassword").innerHTML ="<font color=red>Kindly enter Old Password....</font>";
		 validatecondtion=1;
	 }
	 if(document.frmchangepassworduser.newpassword.value.length < 8)
	 {
		 document.getElementById("idnewpassword").innerHTML ="<font color=red>Password must contain at least 8 characters..</font>";
		 validatecondtion=1;
	 }
	 if(document.frmchangepassworduser.newpassword.value=="")
	 {
		 document.getElementById("idnewpassword").innerHTML ="<font color=red>Password should not be empty..</font>";
		 validatecondtion=1;
	 }
	 if(document.frmchangepassworduser.newpassword.value!=document.frmchangepassworduser.confirmpassword.value)
	 {
		 document.getElementById("idconfirmpassword").innerHTML ="<font color=red>Password and Confirm password are not matching..</font>";
		 validatecondtion=1;
	 }	 
	   if(document.frmchangepassworduser.confirmpassword.value=="")
	 {
		 document.getElementById("idconfirmpassword").innerHTML ="<font color=red>Confirm Password should not be empty..</font>";
		 validatecondtion=1;
	 }
	  if(validatecondtion==1)
	 {
		 return false;
	 }
	 else
	 {
		 return true;
	 }
 }
 </script>