function changeValue(){
var price=0;
 if (document.eco_art_Form.os0.selectedIndex == 0){
	price = 125;
 	document.eco_art_Form.amount.value = price.toFixed(2);
 }else if (document.eco_art_Form.os0.selectedIndex == 1){
	price = 200;
 	document.eco_art_Form.amount.value = price.toFixed(2);
 }
}