function changeClass(id, class_name) {
	document.getElementById(id).className = class_name;	
}

function setOverFind(id) {
	document.getElementById(id).src = "pic/find_button_not_over.jpg";
}

function setNotOverFind(id) {
	document.getElementById(id).src = "pic/find_button.jpg";
}

function setOverMainFind(id) {
	document.getElementById(id).src = "pic/main_not_over_find_button.jpg";
}

function setNotOverMainFind(id) {
	document.getElementById(id).src = "pic/main_find_button.jpg";
}

function changeText(id, text) {
	document.getElementById(id).value = text;
}

function setDefaultText(id, text) {
	if (document.getElementById(id).value == '') {
		document.getElementById(id).value = text;
	}
}