// Check that only numbers are entered

function numeralsOnly(evt) {
    evt = (evt) ? evt : event;
    var charCode = (evt.charCode) ? evt.charCode : ((evt.keyCode) ? evt.keyCode : 
        ((evt.which) ? evt.which : 0));

    if (charCode == 13) { // keep enter key from deleting fields
        return false;
    }

    if (charCode > 31 && (charCode < 48 || charCode > 57) && charCode != 46) {
        alert("Enter numerals only in this field.");
        return false;
    }
    return true;
}