function sinchro( current_form ) {
	for(var count = 0; count < current_form.length; count++  ) {
		document.topform.elements[ count ].checked = current_form.elements[ count ].checked;
		document.bottomform.elements[ count ].checked = current_form.elements[ count ].checked;
	}
}

function check2( current_form ) {
	var checkednum = 0;
	for(var count = 0; count < current_form.length; count++  ) {
		if( current_form.elements[ count ].type == "checkbox" ){
			if(current_form.elements[ count ].checked == true) checkednum++;
		}
	}
	if(checkednum<2) {
		alert("Необходимо выбрать не менее 2 моделей");
		return false;
	}
	return true;
}