function NumbersOnly( myfield, e, dec )
{
    var key;
    var keychar;

    if( window.event )
        key = window.event.keyCode;
    else if( e )
        key = e.which;
    else
        return true;
    keychar = String.fromCharCode( key );

    // control keys
    if( ( key == null ) || ( key == 0 ) || ( key == 8 ) || ( key == 9 ) || ( key == 13 ) || ( key == 27 ) )
        return true;

    // numbers
    else if( ( ( "0123456789" ).indexOf( keychar ) > -1 ) )
        return true;

    // decimal point jump
    else if( dec && ( keychar == "." ) ) {
        myfield.form.elements[dec].focus( );
        return false;
    }
    else {
        return false;
    }
}