It really helps if you mention Unity too in the title or the tags, very few know what programming system you use.

I try use http://www.coatbros.com/blog/2015/03/ but it dont work.I dont know why.

Come on https://www.twitch.tv/rasetocsgo to help me.

A line check should work in this case as long as the sprite origins are at the feet, not the center or top. Check in your sprite import settings, or apply the sprite/bounding box height as an offset.

EDIT: Looking at the code, Vector3.Set doesn't work on transform vectors. You have to manually set the entire vector reference to a separate Vector object:

if (transform.position.y > Object.transform.position.y) {
{
        // doesn't work
        transform.position.Set(transform.position.x, transform.position.y, -1);

        // does work
        transform.position = new Vector3(transform.position.x, transform.position.y, -1);
}

A line check should work in this case as long as the sprite origins are at the feet, not the center or top. Check in your sprite import settings, or apply the sprite/bounding box height as an offset.

EDIT: Looking at the code, Vector3.Set doesn't work on transform vectors. You have to manually set the entire vector reference to a separate Vector object:

if (transform.position.y > Object.transform.position.y) {
{
        // doesn't work
        transform.position.Set(transform.position.x, transform.position.y, -1);

        // does work
        transform.position = new Vector3(transform.position.x, transform.position.y, -1);
}

Object.transform doesn't exist

http://i.imgur.com/VecpKVU.png

http://pastebin.com/kF67xrwt

That was copy and pasted from your original code. Making a new Vector3 is the main point.

Look still dont work: http://i.imgur.com/h17uIzb.png