-------------------------------------------------
Let me know your thoughts and questions in the comments.
Email: vyasankit2008@gmail.com

//Multiple Select Drop Down Code
<div class="multiselect" id="multiple">
    <?php
    global $wpdb;
    $getid= $_GET['id'];
    $sql11 = "SELECT * FROM TABLENAME WHERE id = '$getid'";
    $result11 = $wpdb->get_results($sql11);
    $count1 = 1;
    foreach($result11 as $row11){?>                             
        <label>
            <input type="checkbox" id="chknote_<?php echo $count1; ?>" name="client_check[]" class="queAns trigger" data-trigger="hidden_fields_<?php echo $count1; ?>" data-trigger-one="hidden_fields_one<?php echo $count1; ?>"  value="<?php echo $count1; ?>" />
            <?php echo $count1; ?>. <?php echo $client->lastname;?>'s <?php echo $row11->goal; ?>
        </label>
    <?php $count1++;}?>
</div>

//multiple select drop down js script
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script>
jQuery(function() {
jQuery(".multiselect").multiselect();
});
jQuery.fn.multiselect = function() {
$(this).each(function() {
var checkboxes = $(this).find("input:checkbox");
checkboxes.each(function(){
var checkbox = $(this);
if (checkbox.prop("checked"))
checkbox.addClass("multiselect-on");
checkbox.click(function() {
if (checkbox.prop("checked")){
checkbox.addClass("multiselect-on");
}else{
checkbox.removeClass("multiselect-on");
}
});
});
});
};
</script>

//open selected option script
<script>
jQuery(function() {
  jQuery('.hidden').hide();
  jQuery('.trigger').change(function() {
var hiddenId = jQuery(this).attr("data-trigger");
if (jQuery(this).is(':checked')) {
  jQuery("#" + hiddenId).show();
} else {
  jQuery("#" + hiddenId).hide();
}

var hiddenId = jQuery(this).attr("data-trigger-one");
if (jQuery(this).is(':checked')) {
  jQuery("#" + hiddenId).show();
} else {
  jQuery("#" + hiddenId).hide();
}

  });
</script>

//open selected option html/php code
<?php
global $wpdb;
$getid = $_GET['getid'];
$sql="SELECT * FROM TableName WHERE id = '$getid'";
$result=$wpdb->get_results($sql);
$count = 1;
foreach($result as $row){?>
<span id="hidden_fields_<?php echo $count; ?>"  style="display: none;">

<?php echo $count; ?>. <?php echo $client->columnName;?>'s <?php echo $row->columnName; ?>:
<p><input type="hidden" name="goal_id[]" value="<?php echo $row->columnName; ?>" /></p>         
<div class="col-md-12"> Notes:
<textarea name="note[]"  class="custom-txt-area" id="hidden_<?php echo $count; ?>"></textarea>
</div>

</span>             
<?php  $count++;} ?>

//css for dropdown
<style>
.queAns{
    margin-right:5px !important;
}
.multiselect {
    width:33em;
    height:10em;
    border:solid 1px #c0c0c0;
    overflow:auto;
    padding:5px;
}

.multiselect label {
    display:block;
}

.multiselect-on {
    color:#ffffff;
    background-color:#d29714;
}
</style>
-------------------------------------------------
Let me know your thoughts and questions in the comments.
Email: vyasankit2008@gmail.com

<?php
//splits a string into an array
echo "splits a string into an array -- ";
$a="this is test string";
$m=str_split($a,4);
print_r($m);

//Compare two strings
echo "<br><br>";
echo "Compare two strings -- ";
$a="gfhgfhgfhfghgfhfghg";
$b="g";
if(strcmp($a,$b)==0)
{
echo "both are same";
}
else
{
echo "both are not same";
}

//calculates the MD5 hash of a string.
echo "<br><br>";
echo "calculates the MD5 hash of a string -- ";
$a="testString";
echo md5($a);

//Convert the first character of each word to uppercase
echo "<br><br>";
echo "Convert the first character of each word to uppercase -- ";
$a="this is test string";
echo ucwords($a);

//searches for the first occurrence of a string inside another string
echo "<br><br>";
echo "searches for the first occurrence of a string inside another string -- ";
$a="teststring";
echo strstr($a,'n');

//removes whitespace and other predefined characters from both sides of a string.
echo "<br><br>";
echo "removes whitespace and other predefined characters from both sides of a string -- ";
$a="   this isTest    ";
echo trim($a);

//formats a number with grouped thousands.
echo "<br><br>";
echo "formats a number with grouped thousands -- ";
$a = 1235655.9857985;
echo number_format($a,4);
?>

-------------------------------------------------
Let me know your thoughts and questions in the comments.
Email: vyasankit2008@gmail.com

<form action="#" method="POST">
  <div> Checkbox 1:
    <input type="checkbox" id="checkbox_one" name="Checkbox1" data-trigger="hidden_checkbox_one" class="trigger">
  </div>  <div id="hidden_checkbox_one" class="hidden"> This is hidden one:
    <input type="text" id="hidden_one" name="hidden">
  </div>
  <div> Checkbox 2:
    <input type="checkbox" id="checkbox_two" name="Checkbox2" data-trigger="hidden_checkbox_two" class="trigger">
  </div>
  <div id="hidden_checkbox_two" class="hidden"> This is hidden two:
    <input type="text" id="hidden_two" name="hidden">
  </div>
  <div> Checkbox 3:
    <input type="checkbox" id="checkbox_three" name="Checkbox3" data-trigger="hidden_checkbox_three" class="trigger">
  </div>
  <div id="hidden_checkbox_three" class="hidden"> This is hidden three:
    <input type="text" id="hidden_three" name="hidden">
  </div>
  <div> Checkbox 4:
    <input type="checkbox" id="checkbox_four" name="Checkbox4" data-trigger="hidden_checkbox_four" class="trigger">
  </div>
  <div id="hidden_checkbox_four" class="hidden"> This is hidden four:
    <input type="text" id="hidden_four" name="hidden">
  </div>
</form>

<script>
jQuery(function() {
  jQuery('.hidden').hide();
  jQuery('.trigger').change(function() { 
    var hiddenId = jQuery(this).attr("data-trigger");
    if (jQuery(this).is(':checked')) {
      jQuery("#" + hiddenId).show();
    } else {
      jQuery("#" + hiddenId).hide();
    }
  });
});
</script>

-------------------------------------------------
Let me know your thoughts and questions in the comments.
Email: vyasankit2008@gmail.com

$to = "xyz@domainname.com";
$subject = "This is subject"; 
$message = "This is HTML message.";
$message .= "This is headline.";
$header = "From:info@domainname.com \r\n"; // domainname.com or domainname.co.in with domain name
$header .= "Cc:test@domainname.com \r\n";
$header .= "MIME-Version: 1.0\r\n";
$header .= "Content-type: text/html\r\n";
$retval = mail ($to,$subject,$message,$header);
if( $retval == true ) {
echo "Message sent successfully...";
}else {
echo "Message could not be sent...";
}
-------------------------------------------------

Let me know your thoughts and questions in the comments.
Email: vyasankit2008@gmail.com