how to check canvas is empty or not

<canvas id="canvas11″ height=”200px” width=”200px”>
<asp:Button runat=”server” ID=”btn1″ Text=”Save”  OnClientClick=”checkcanvas();” />
<script type=”text/javascript”>
function checkcanvas() {
var i = isCanvasTransparent();
//i =true    if canvas empty
//i =false       if canvas has image
}
function isCanvasTransparent() {
var canvas1 = document.getElementById(‘canvas11′);
// true if all pixels Alpha equals to zero
var ctx = canvas1.getContext(“2d”);
var result;
var imageData = ctx.getImageData(0, 0, canvas1.offsetWidth, canvas1.offsetHeight);
for (var i = 0; i < imageData.data.length; i += 4)
if (imageData.data[i + 3] !== 0) return false;
return true;
}
</script>

countdown timer in php,

$dateFormat = “d F Y — g:i a”;
$targetDate = $futureDate;//Change the 25 to however many minutes you want to countdown change date in strtotime
$actualDate = $date1;
$secondsDiff = $targetDate – $actualDate;
$remainingDay     = floor($secondsDiff/60/60/24);
$remainingHour    = floor(($secondsDiff-($remainingDay*60*60*24))/60/60);
$remainingMinutes = floor(($secondsDiff-($remainingDay*60*60*24)-($remainingHour*60*60))/60);
$remainingSeconds = floor(($secondsDiff-($remainingDay*60*60*24)-($remainingHour*60*60))-($remainingMinutes*60));
$actualDateDisplay = date($dateFormat,$actualDate);
$targetDateDisplay = date($dateFormat,$targetDate);
<script type=”text/javascript”>
var days = <?php echo $remainingDay; ?>
var hours = <?php echo $remainingHour; ?>
var minutes = <?php echo $remainingMinutes; ?>
var seconds = <?php echo $remainingSeconds; ?>
function setCountDown(statusfun)
{//alert(seconds);
var SD;
if(days >= 0 && minutes >= 0){
var dataReturn =  jQuery.ajax({
type: “GET”,
url: “<?php echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_WEB).’index.php/countdowncont/’; ?>”,
async: true,
success: function(data){
var data = data.split(“/”);
day =  data[0];
hours =  data[1];
minutes =  data[2];
seconds =  data[3];
}
});
seconds–;
if (seconds < 0){
minutes–;
seconds = 59
}
if (minutes < 0){
hours–;
minutes = 59
}
if (hours < 0){
days–;
hours = 23
}
document.getElementById(“remain”).style.display = “block”;
document.getElementById(“remain”).innerHTML = ” Your Product Reverse For “+minutes+” minutes, “+seconds+” seconds”;
SD=window.setTimeout( “setCountDown()”, 1000 );
}else{
document.getElementById(“remain”).innerHTML = “”;
seconds = “00″; window.clearTimeout(SD);
jQuery.ajax({
type: “GET”,
url: “<?php echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_WEB).’index.php/countdown/’; ?>”,
async: false,
success: function(html){
}
});
document.getElementById(“remain”).innerHTML = “”;
window.location = document.URL; // Add your redirect url
}
}
</script>
<?php
if($date1 < $futureDate &&  ($qtyCart > 0)){ ?>
<script type=”text/javascript”>
setCountDown();
</script>
<?php }else{ ?>
<style>
#remain{display:none;}
</style>
<?php }}?>
<div id=”remain”></div>

how to check canvas is empty or not

<canvas11″ height=”200px” width=”200px”>
<asp:Button runat=”server” ID=”btn1″ Text=”Save”  OnClientClick=”checkcanvas();” />
<script type=”text/javascript”>
function checkcanvas() {
var i = isCanvasTransparent();
//i =true    if canvas empty
//i =false       if canvas has image
}
function isCanvasTransparent() {
var canvas1 = document.getElementById(‘canvas11′);
// true if all pixels Alpha equals to zero
var ctx = canvas1.getContext(“2d”);
var result;
var imageData = ctx.getImageData(0, 0, canvas1.offsetWidth, canvas1.offsetHeight);
for (var i = 0; i < imageData.data.length; i += 4)
if (imageData.data[i + 3] !== 0) return false;
return true;
}
</script>

countdown timer in php,

$dateFormat = “d F Y — g:i a”;
$targetDate = $futureDate;//Change the 25 to however many minutes you want to countdown change date in strtotime
$actualDate = $date1;
$secondsDiff = $targetDate – $actualDate;
$remainingDay     = floor($secondsDiff/60/60/24);
$remainingHour    = floor(($secondsDiff-($remainingDay*60*60*24))/60/60);
$remainingMinutes = floor(($secondsDiff-($remainingDay*60*60*24)-($remainingHour*60*60))/60);
$remainingSeconds = floor(($secondsDiff-($remainingDay*60*60*24)-($remainingHour*60*60))-($remainingMinutes*60));
$actualDateDisplay = date($dateFormat,$actualDate);
$targetDateDisplay = date($dateFormat,$targetDate);
<script type=”text/javascript”>
var days = <?php echo $remainingDay; ?>
var hours = <?php echo $remainingHour; ?>
var minutes = <?php echo $remainingMinutes; ?>
var seconds = <?php echo $remainingSeconds; ?>
function setCountDown(statusfun)
{//alert(seconds);
var SD;
if(days >= 0 && minutes >= 0){
var dataReturn =  jQuery.ajax({
type: “GET”,
url: “<?php echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_WEB).’index.php/countdowncont/’; ?>”,
async: true,
success: function(data){
var data = data.split(“/”);
day =  data[0];
hours =  data[1];
minutes =  data[2];
seconds =  data[3];
}
});
seconds–;
if (seconds < 0){
minutes–;
seconds = 59
}
if (minutes < 0){
hours–;
minutes = 59
}
if (hours < 0){
days–;
hours = 23
}
document.getElementById(“remain”).style.display = “block”;
document.getElementById(“remain”).innerHTML = ” Your Product Reverse For “+minutes+” minutes, “+seconds+” seconds”;
SD=window.setTimeout( “setCountDown()”, 1000 );
}else{
document.getElementById(“remain”).innerHTML = “”;
seconds = “00″; window.clearTimeout(SD);
jQuery.ajax({
type: “GET”,
url: “<?php echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_WEB).’index.php/countdown/’; ?>”,
async: false,
success: function(html){
}
});
document.getElementById(“remain”).innerHTML = “”;
window.location = document.URL; // Add your redirect url
}
}
</script>
<?php
if($date1 < $futureDate &&  ($qtyCart > 0)){ ?>
<script type=”text/javascript”>
setCountDown();
</script>
<?php }else{ ?>
<style>
#remain{display:none;}
</style>
<?php }}?>
<div id=”remain”></div>