jQuery Cascade Plugin

this is a simple jQuery plugin for cascading drop downs with the following features:

• filling a single drop down depending on multiple drop downs.
• adding extra arguments.
• specifying a request type (GET or POST).
• specifying a function to be executed before starting the request.
• specifying a function to be executed after completing the request.

Options:

dependent (required):

the ID of the dependent drop down.

url (required):

the url from where to get the data.

textKey (required):

the key that will be used for getting the text of an item after parsing the returned result.

valueKey (required):

the key that will be used for getting the value of an item after parsing the returned result.

argName (required):

the argument name to be used when sending request.

onError:

the function to be executed if an error occured while sending the request.

onComplete:

the function to be executed after request is complete.

beforeRequest

the function to be executed before the request starts.

defualtItemText:

the text to be used for the default item in the dependent drop down.

extraParam:

an object that contains the extra parameters to be send with the request (for example {param1 : value1}).

additionalDDL:

an array of objects (just the argument name and the ID of the drop down) that represents the additional drop downs to send its values with the request (for example [{ argName: "val2", ID: "additionalDDL1" }, { argName: "val3", ID: "additionalDDL2" }]).

requestType:

a string that represents the request type (GET or POST), the default request type is GET.

Sample usage:

$("#Combo2").cascade({
    url: "/Data/GetData",
    dependent : "Combo3",
    textKey: "Text",
    valueKey: "Value",
    defualtItemText: "select an item",
    argName: "val1",
    additionalDDL: [{ argName: "val2", ID: "Combo1" }],
    beforeRequest: function () { alert("before satrt"); },
    onComplete: function () { alert("complete"); },
    requestType: "POST"
});