Javascript Samples to be used with the CSS Custom field

window.addEvent('domready', function(){
	// Configuration
	var maxlen	= 300; // Number of characters allowed
	var fieldID	= 'cf_50'; // Custom Field ID: In this case the Custom Field ID is 50 
	var charsLeftMsg= ' characters left'; // Characters Left Message
	// Configuration ends;
 
	var field	= $(fieldID);
	// Inject new HTML;
	var charsLeft	= new Element('div', {id: fieldID+'-chars-left'});
	var charsLeftBox= new Element('span', {id: fieldID+'-chars-left-field'});
	var charsLeftTxt= new Element('span', {id: fieldID+'-chars-left-txt'});
	charsLeftBox.inject(charsLeft);
	charsLeftTxt.inject(charsLeftBox,'after');
	charsLeftTxt.set('text',charsLeftMsg);
	charsLeftBox.set('text',maxlen);
	charsLeft.inject(field,'after');
	// Add behaviour to field
	field.addEvent('keyup', function(e) {
		new Event(e).stop();
		var fieldValue		= field.get('value');
		fieldValue		= fieldValue.substring(0, maxlen);
		field.set('value', fieldValue);
		var fieldLength = fieldValue.length;
		charsLeftBox.set('text', (maxlen - fieldLength) );
	});
});