manage_request.php

<?php 
include 'db_connect.php'; 
if(isset($_GET['id'])){
$qry = $conn->query("SELECT * FROM requests where id= ".$_GET['id']);
foreach($qry->fetch_array() as $k => $val){
	$$k=$val;
}
}
?>
<div class="container-fluid">
    <form action="" id="manage-request">
        <input type="hidden" name="id" value="<?php echo isset($id) ? $id : '' ?>">
        <div id="msg"></div>
        <div class="form-group">
            <label for="" class="control-label">Patient Full Name</label>
            <input type="text" class="form-control" name="patient" value="<?php echo isset($patient) ? $patient :'' ?>"
                required>
        </div>
        <div class="form-group">
            <label for="" class="control-label">Blood Group</label>
            <select name="blood_group" id="" class="custom-select select2" required>
                <option value=""></option>
                <option <?php echo isset($blood_group) && $blood_group == 'A+' ? ' selected' : '' ?>>A+</option>
                <option <?php echo isset($blood_group) && $blood_group == 'B+' ? ' selected' : '' ?>>B+</option>
                <option <?php echo isset($blood_group) && $blood_group == 'O+' ? ' selected' : '' ?>>O+</option>
                <option <?php echo isset($blood_group) && $blood_group == 'AB+' ? ' selected' : '' ?>>AB+</option>
                <option <?php echo isset($blood_group) && $blood_group == 'A-' ? ' selected' : '' ?>>A-</option>
                <option <?php echo isset($blood_group) && $blood_group == 'B-' ? ' selected' : '' ?>>B-</option>
                <option <?php echo isset($blood_group) && $blood_group == 'O-' ? ' selected' : '' ?>>O-</option>
                <option <?php echo isset($blood_group) && $blood_group == 'AB-' ? ' selected' : '' ?>>AB-</option>
            </select>
        </div>

        <!-- <div class="form-group">
			<label for="" class="control-label">Available Volume (L)</label>
			<input type="number" class="form-control text-right" step="any" name="avolume"  value="0" readonly="">
		</div> -->

        <div class="form-group">
            <label for="" class="control-label">Volume (L)</label>
            <input type="number" class="form-control" name="volume"
                value="<?php echo isset($volume) ? $volume / 1000 :'' ?>" required>
        </div>
        <div class="form-group">
            <label for="" class="control-label">Physician Name</label>
            <input type="text" class="form-control" name="physician_name"
                value="<?php echo isset($physician_name) ? $physician_name :'' ?>" required>
        </div>
        <?php if(isset($status)): ?>
        <div class="form-group">
            <label for="" class="control-label">Status</label>
            <select name="status" id="" class="custom-select select2" required>
                <option value="0" <?php echo $status == 0 ? 'selected' : ''  ?>>Pending</option>
                <option value="1" <?php echo $status == 1 ? 'selected' : ''  ?>>Approved</option>
            </select>
        </div>
        <?php endif; ?>
</div>
</form>
</div>
<script>
$(document).ready(function() {
    if ('<?php echo isset($blood_group)? 1:0 ?>' == 1)
        $('[name="blood_group"]').trigger('change')
})
$('[name="blood_group"]').change(function() {
    var _id = $(this).val()
    console.log(_id)
    // $.ajax({
    // 	url:'ajax.php?action=get_available',
    // 	method:'POST',
    // 	data:{blood_group:$(this).val(),id:'<?php
    //  echo isset($id)? $id : '' 
    // 	 ?>'},
    // 	success:function(resp){
    // 		if(resp > 0){
    // 			$('[name="avolume"]').val(resp)
    // 		}else{
    // 			$('[name="avolume"]').val(0)
    // 		}
    // 	}
    // })
})
$('#manage-request').submit(function(e) {
    e.preventDefault()
    start_load()
    $('#msg').html('')
    // if ($('[name="volume"]').val() > $('[name="avolume"]').val()) {
    //     $('#msg').html('<div class="alert alert-danger">Blood volume is greater than available volume.</div>')
    //     end_load()
    //     return false;
    // }
    $.ajax({
        url: 'ajax.php?action=save_request',
        data: new FormData($(this)[0]),
        cache: false,
        contentType: false,
        processData: false,
        method: 'POST',
        type: 'POST',
        success: function(resp) {
            if (resp == 1) {
                alert_toast("Data successfully saved.", 'success')
                setTimeout(function() {
                    location.reload()
                }, 1000)
            }
        }
    })
})
</script>