function FormData(form_id){
	this.form = $(form_id);
	this.clear();
}

FormData.prototype = {
	any_changes: function(){
		if (!this.has_data) return false;
		var fd=this;
		
		var changes = false;
		foreach(this.form.getElementsByTagName("input"),
			function(input){
				if (input.type == "text" && fd.original_values[input.id]!=input.value){
					changes = true;
					return true;
				}
			});
			
		return changes;
	},
	
	save: function(){
		this.original_values = new Object();
		var fd=this;
	
		foreach(this.form.getElementsByTagName("input"),
			function(input){
				if (input.type == "text")
					fd.original_values[input.id]=input.value;
			});
			
		this.has_data = true;
	},
	
	clear: function(){
		this.original_values = new Object();
		this.has_data = false;
	}
};