v = new Array();
v[1] = new Array(31, 0.7, 8.1) //rur, eur, uah. conv.rbc.ru

function valconv (t, m)
{   for (i = 1; i <= m; i++)
    {   switch (t)
        {   case '1':
            document.getElementById('pr_' + i).innerHTML = document.getElementById('usd_' + i).innerHTML;
            break;
            case '2':
            document.getElementById('pr_' + i).innerHTML = (document.getElementById('usd_' + i).innerHTML * v[1][0]).toFixed(2);
            break;
            case '3':
            document.getElementById('pr_' + i).innerHTML = (document.getElementById('usd_' + i).innerHTML * v[1][1]).toFixed(2);
            break;
            case '4':
            document.getElementById('pr_' + i).innerHTML = (document.getElementById('usd_' + i).innerHTML * v[1][2]).toFixed(2);
            break;
        }
    }
}