void Start()
    {
        tower            = null;
        buildplace       = null;
        s_clickdmgbtn    = upgdmgobj.GetComponent <clickdmgbtn>();
        s_clickspdbtn    = upgspdobj.GetComponent <clickspdbtn>();
        s_clickrngbtn    = upgrngobj.GetComponent <clickrngbtn>();
        s_clicksellbtn   = sellobj.GetComponent <clicksellbtn>();
        s_clickcanclebtn = cancleobj.GetComponent <clickcanclebtn>();
        upgcanvas.GetComponent <Canvas>().enabled = false;

        upgcanvas2.GetComponent <Canvas>().enabled = false;
        s_buildtower1 = buildtowerobj1.GetComponent <buildtower1>();
        s_buildtower2 = buildtowerobj2.GetComponent <buildtower2>();
        s_buildtower3 = buildtowerobj3.GetComponent <buildtower3>();
    }
    void Start()
    {
        tower = null;
        buildplace = null;
        s_clickdmgbtn = upgdmgobj.GetComponent<clickdmgbtn>();
        s_clickspdbtn = upgspdobj.GetComponent<clickspdbtn>();
        s_clickrngbtn = upgrngobj.GetComponent<clickrngbtn>();
        s_clicksellbtn = sellobj.GetComponent<clicksellbtn>();
        s_clickcanclebtn = cancleobj.GetComponent<clickcanclebtn>();
        upgcanvas.GetComponent<Canvas>().enabled = false;

        upgcanvas2.GetComponent<Canvas>().enabled = false;
        s_buildtower1 = buildtowerobj1.GetComponent<buildtower1>();
        s_buildtower2 = buildtowerobj2.GetComponent<buildtower2>();
        s_buildtower3 = buildtowerobj3.GetComponent<buildtower3>();
    }