Scale Objects become flat.

I'm unable to scale an GameObject correctly. The goal is to drag the mouse and make the size of that object bigger or smaller. with the following code I can scale it bigger in two dimensions but the other dimension is flat.(I can post a picture if you'd like an example).

function OnMouseDown()
{
    myselector = Instantiate(selectorring, slightlyup,Quaternion.identity);
    originalmousepoint = camera.main.ScreenToViewportPoint(Input.mousePosition);
}
function OnMouseDrag  () 
{
    radius = Vector3.Distance(originalmousepoint, camera.main.ScreenToViewportPoint(Input.mousePosition))*100;
    myselector.transform.localScale=new Vector3(myselector.transform.localScale.x*radius, transform.localScale.y*radius, transform.localScale.z*radius);
}

I'm stumped because with other code for scaling it doesn't scale as I drag.