function roundNumber(rnum, rlength) { // Arguments: number to round, number of decimal places
  var newnumber = Math.round(rnum*Math.pow(10,rlength))/Math.pow(10,rlength);
  document.roundform.numberfield.value = newnumber; // Output the result to the form field (change for your purposes)
}

function calculateCurrency(type) {

	if(type==1) {

		var first_value = document.getElementById('sk1').value;
		var recalculate = Math.round((first_value/30.1260)*1000)/1000;
		
		document.getElementById('eur1').value = recalculate;
	
	} else if (type==2) {
	
		var first_value = document.getElementById('eur2').value;
		document.getElementById('sk2').value = Math.round((first_value*30.1260)*1000)/1000;
	
	} else if (type==3) {
	
		var first_value = document.getElementById('eur1').value;
		document.getElementById('sk1').value = Math.round((first_value*30.1260)*1000)/1000;
	
	} else if (type==4) {
	
		var first_value = document.getElementById('sk2').value;
		document.getElementById('eur2').value = Math.round((first_value/30.1260)*1000)/1000;
	
	}

}