// Disables gravity on all rigid bodies entering this collider.
function OnTriggerEnter (other : Collider) {
    if (other.attachedRigidbody) {
        other.attachedRigidbody.useGravity = false;
    }
}
// Turn this collider into a trigger on startup
collider.isTrigger = true;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void OnTriggerEnter(Collider other) {
        if (other.attachedRigidbody)
            other.attachedRigidbody.useGravity = false;
        
    }
    void Example() {
        collider.isTrigger = true;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def OnTriggerEnter(other as Collider):
        if other.attachedRigidbody:
            other.attachedRigidbody.useGravity = false

    def Example():
        collider.isTrigger = true