var itemNum = "4";
var itemCurrent = 0;
function form_go(step) {
	// hide the current screen, except the last screen
	if (itemCurrent==4 && window.do_data_validate_4) {
		if (!do_data_validate_4()) {
			return;
		}
	}

	if (itemCurrent>0 && itemCurrent<itemNum) {
		gObj_1 = document.getElementById("divForm_" + itemCurrent);
		if (gObj_1) {
			gObj_1.style.visibility = "hidden";
		}
	}
	itemCurrent += step;
	if (itemCurrent<=0) {
		itemCurrent = 1;
	} else if (itemCurrent>itemNum) {
		obj_1 = document.getElementById("frmMain");
		if (obj_1) {
			alert("Submit data now...");
			obj_1.submit();
		}
		return;
	}
	
	// show the new screen
	gObj_2 = document.getElementById("divForm_" + itemCurrent);
	if (gObj_2) {
		gObj_2.style.visibility = "visible";
	}
	
}