call change() event handler if I select radio button programatically

$(function () {

    $('input[name=type]').change(function () {
        alert($(this).val());
    });
    $('input[value=SV]').attr('checked', 'checked').trigger('change');
});

Change an Image while using JCrop

Initialize jCrop

var jcrop_api;
        function InitjCrop() {
            $('#id').Jcrop({  }, function () {
                jcrop_api = this;
            });
        }

To unhook jCrop

jcrop_api.destroy();

To Hook jCrop again

InitjCrop();

Inserting text after cursor position in text areа

$.fn.extend({
                   insertAtCaret: function (myValue) {
                        if (!this.selectionStart)
                            thi = $(this).get(0);
                        if (thi.selectionStart || thi.selectionStart == '0') {
                            var startPos = thi.selectionStart;
                            var endPos = thi.selectionEnd;
                            var scrollTop = thi.scrollTop;
                            thi.value = thi.value.substring(0, startPos) + myValue + thi.value.substring(endPos, thi.value.length);
                            thi.focus();
                            thi.selectionStart = startPos + myValue.length;
                            thi.selectionEnd = startPos + myValue.length;
                            thi.scrollTop = scrollTop;
                        } else {
                            thi.value += myValue;
                            thi.focus();
                        }
                    }
                })

Convert jQuery object to DOM object

jQuery Object

$('textarea')

example of setting a value

$('textarea').val("Hi");

DOM object

$('textarea').get(0)

example of setting a value

$('textarea').get(0).value = "Hi";

jQuery how to check html input checkbox state

$("input[type=checkbox]").change(function () {
     var isChecked = this.checked;
     if (isChecked) {
          //rest goes here
     }
});

JavaScript URL encode

encodeURIComponent(str);

jQuery get specific option tag text

$("#list option:selected").text();

How to check whether an DOM element exists using JQuery(JS)

If you every want to check whether an element exists using JavaScript or jQuery, just use this snippet

if ( $("selector").length ) {
// rest goes here
}

Parsing UK Date in javascript

To reach a date object with UK format in javascript has no straight road. Well you can use split map to reach there.
Consider this example
var ukDate = new Date("01/12/2011");
well for javascript it is
Wed Jan 12 2011 00:00:00
but we can use the split() object to first separate the date using “/” as separator and then create the Date Object
Consider this example

var ukDate="01/12/2011";

var dateArray=ukDate.split("/");

var newDate=new Date(dateArray[2], dateArray[1]-1,dateArray[0]);

not output will be
Thu Dec 01 2011
and your are done