book-appointment .php

<script>
function getdoctor(val) {
	$.ajax({
	type: "POST",
	url: "../get_doctor.php",
	data:'specilizationid='+val,
	success: function(data){
		$("#doctor").html(data);
	}
	});
}
</script>	

<script>
function getAppNumber(val) {
	$.ajax({
	type: "POST",
	url: "../get_doctor.php",
	data:'doctor='+val,
	success: function(data){
		$("#AppNumber").html(data);
	}
	});
}
</script>	


<script>
function getfee(val) {
	$.ajax({
	type: "POST",
	url: "../get_doctor.php",
	data:'doctor='+val,
	success: function(data){
		$("#fees").html(data);
	}
	});
}
</script>

<div class="form-group">
	<label for="DoctorSpecialization">
		Doctor Specialization
	</label>
	<select name="Doctorspecialization" class="form-control" onChange="getdoctor(this.value);" required="required">
		<option value="">Select Specialization</option>
		<?php 
			$ret=mysqli_query($con,"select * from doctorspecilization");
		        while($row=mysqli_fetch_array($ret))
			{
			?>
		<option value="<?php echo htmlentities($row['specilization']);?>">
		<?php echo htmlentities($row['specilization']);?>
		</option>
		<?php } ?>
							
	</select>
</div>



<div class="form-group">
        <label for="doctor">
	     Doctor
	</label>
	<select name="doctor" class="form-control" id="doctor" onChange="getfee(this.value);getAppnumber(this.value);" required="required">
	       <option value="">Select Doctor</option>
	</select>
</div>
	<div class="form-group">
		<label for="consultancyfees">
		         Consultancy Fees
		</label>
	<select name="fees" class="form-control" id="fees"  readonly>

	</select>
</div>
<div class="form-group">
	<label for="appinmentnumber">
		Appoinment Number
	</label>
	<select name="AppNumber" class="form-control" id="AppNumber"  readonly>
	</select>
</div>

get_doctor.php

<?php
include('include/config.php');
if(!empty($_POST["specilizationid"])) 
{

 $sql=mysqli_query($con,"select doctorName,id from doctors where specilization='".$_POST['specilizationid']."'");?>
 <option selected="selected">Select Doctor </option>
 <?php
 while($row=mysqli_fetch_array($sql))
 	{?>
  <option value="<?php echo htmlentities($row['id']); ?>"><?php echo htmlentities($row['doctorName']); ?></option>
  <?php
}
}


if(!empty($_POST["doctor"])) 
{

 $sql=mysqli_query($con,"select docFees from doctors where id='".$_POST['doctor']."'");
 while($row=mysqli_fetch_array($sql))
 	{?>
 <option value="<?php echo htmlentities($row['docFees']); ?>"><?php echo htmlentities($row['docFees']); ?></option>
  <?php
}
}

if(!empty($_POST["doctor"])) 
{

 $sql=mysqli_query($con,"select doctorId,COUNT(AppNumber)+1 as nextAppNumber from appointment  where doctorId='".$_POST['doctor']."' group by doctorId order by doctorId DESC");
 while($row=mysqli_fetch_array($sql))
 	{?>
 <option value="<?php echo htmlentities($row['nextAppNumber']); ?>"><?php echo htmlentities($row['nextAppNumber']); ?></option>
  <?php
}
}

?>

Thank you for help