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.currency.result.value = "Funkade inte";
		  } else {   
		        document.currency.result.value=document.currency.sum.value*(document.currency.currency1.options[document.currency.currency1.selectedIndex].value/document.currency.currency2.options[document.currency.currency2.selectedIndex].value);
				document.currency.result.value="= " + Math.round(document.currency.result.value*100)/100 + " " + document.currency.currency2.options[document.currency.currency2.selectedIndex].text.substr(0,3); 
				document.currency.info.value=document.currency.sum.value + " " + document.currency.currency1.options[document.currency.currency1.selectedIndex].text.substr(0,3);   
				  }  
				 }