on change dropdown jquery code example

Example 1: jquery select box change event

$('select').on('change', function (e) {
    var optionSelected = $("option:selected", this);
    var valueSelected = this.value;
    ....
});

Example 2: dropdown option selection change event in jquery

$("select [name='element_name']").change(function(){
	// condition goes here
});

Example 3: jquery detect textarea change

$('#myTextAreaID').on('input propertychange paste', function() {
    //my Textarea content has changed
});