Weird passing php string to javascript sometimes not work

how i what it to work: goal: make a album viewer without reload the page, with a img html element, change img SRC dynamically with javascript, but image url's stored in php variables and what copy to javascript array. Problem: example have album where have 17 picture, if i echo in php then $i count from 1-17 but in javascript count to 2-12 and 15-17 so ignore 1,13,14 etc. have no ideea why because no difference in data, so DataPicId[13] is undefined but 15th index or 12th index got value normally.

while($row = mysql_fetch_array($SQLpic))
{
$i=$i+1;
$PicId=$row['id'];
$Url=$row['url'];
$Desc=" ".$row['description'];
$UpUser=$row['uploader'];
$Update=$row['udate'];
echo"<script>
nr=Number('".$i."');alert(nr);
DataPicId[nr]=Number('".$PicId."');
DataPicUrl[nr]='".$Url."';
DataPicDesc[nr]='".$Desc."';
DataPicUser[nr]=Number('".$UpUser."');
DataPicDate[nr]='".$Update."';
alert(DataPicUrl[nr]);
</script>";
$ThumbUrl=GetNameOnly($Url);
echo "<div id='PicBoxOut'>
<div id='PicBoxIn' onclick=SelectSrc('".$i."');>
<a href='javascript:void(0);'>
<img src='".$ThumbUrl."' border='0'></a>
</div></div>";