Upload file extension restriction in jquery

Image upload field only accept following extension gif, png, jpg,jpeg.

<form action="" method="post" enctype="multipart/form-data">
Upload Image:<input type="file" name="image" id="image_id"  />
</form>

following code used to limit the upload file extension

<script type="text/javascript">
$(function() {
   $('#image_id').change( function() {
    var ext = $('#image_id').val().split('.').pop().toLowerCase();
    if($.inArray(ext, ['gif','png','jpg','jpeg']) == -1) {
      $('#image_id').val("");
        alert('Please Enter the files in the format jpeg,gif,png');
       
    }
   });
});
</script>

Hide after current date in jquery datepicker

If use date picker for Date of birth, need to hide after current date in date picker.
In jquery date picker maxDate is user to hide the dates after current date.

Assign maxDate to current date.

<script type="text/javascript">
<!--

var currentTime = new Date()
var month = currentTime.getMonth() + 1
var day = currentTime.getDate()
var year = currentTime.getFullYear()

$(document).ready(function(){
    $('#DOB1').datepick({
    yearRange: '-90:+10',
    dateFormat: 'mm/dd/yyyy',
    maxDate: 'month/day/year',
    altField: '#DOB1_alt',
    showTrigger: '<img src="images/calendar.gif" alt="Popup" class="trigger">',
    onSelect: function(dates) {
        
    var date = dates[0];
    $('#DOB1_alt').val(date);
    }
    });
    });  

//-->
</script></div>