drawline2

drawLine : function( x1, y1, x2, y2 ) {

    var x = x1 - x2,
        y = y1 - y2,
        length = Math.sqrt( ( x * x ) + ( y * y ) ),
        angle  = Math.atan2( y2 - y1, x2 - x1 ) * 180 / Math.PI, 
        transform = 'rotate(' + angle + 'deg)';

    var line = $( '<div>' )
        .appendTo( 'body' )
        .css( {
            'position' : 'absolute',
            'transform' : transform,
            'left' : x1,
            'top' : y1
        } )
        .width( length );
    return line;
}