function convert(){ 
	if(!(document.currency.sum.value)) { 
		document.currency.result.value = ""; 
		document.currency.info.value = "";
	} else if ((document.currency.currency1.options[document.currency.currency1.selectedIndex].value == -1) || (document.currency.currency2.options[document.currency.currency2.selectedIndex].value == -1)) {
		document.getElementById('to').innerHTML = "Error";
	} else {   
		document.getElementById('to').innerHTML=document.currency.sum.value*(document.currency.currency1.options[document.currency.currency1.selectedIndex].value/document.currency.currency2.options[document.currency.currency2.selectedIndex].value);
		document.getElementById('to').innerHTML="" + Math.round(document.getElementById('to').innerHTML*1000)/1000 + " " + document.currency.currency2.options[document.currency.currency2.selectedIndex].text.substr(0,3); 
		document.getElementById('from').innerHTML="" + Math.round(document.currency.sum.value*1000)/1000 + " " + document.currency.currency1.options[document.currency.currency1.selectedIndex].text.substr(0,3); 
	}  
}