here is the line of code with the error: function minusmana () {

the error im getting says: Type "Player" already has a definition for "minusmana".

does anyone know what it means?

here is the whole script:

var lefthand : Transform;
var righthand : Transform;
var spell : GameObject;
var spell1 : GameObject;
var spell2 : GameObject;
var spell3 : GameObject;
var spell4 : GameObject;
var spell5 : GameObject;
var spell6 : GameObject;
var spell7 : GameObject;
var spell8 : GameObject;
var spell9 : GameObject;
var spell10 : GameObject;
var spell4u = 0;
var spell5u = 0;
var spell6u = 0;
var spell7u = 0;
var spell8u = 0;
var spell9u = 0;
var spell10u = 0;
var health = 100;
var mana = 100;
var maxHealth = 100;
var dummy = 0;
var minusmana = 0;


function Start () {
spell = spell1;
Invoke("recharge",0.1);
minusmana = 10;
}

function recharge () {
mana += 0.5;
health += 0.1;
Invoke("recharge",0.1);
}

function minusmana () {
mana -= minusmana;
}

function Update () {

if (mana >= maxHealth){
mana =  maxHealth;
}

if (health >= maxHealth){
health =  maxHealth;
}

if(Input.GetButtonDown("Fire1")){
if(mana >= minusmana){
Instantiate(spell, lefthand.position, lefthand.rotation);
Invoke("minusmana",0);
}
}

if(Input.GetButtonDown("Fire2")){
if(mana >= minusmana){
Instantiate(spell, righthand.position, righthand.rotation);
Invoke("minusmana",0);
}
}

if(Input.GetKeyDown("1")){
spell = spell1;
minusmana = 10;
}

if(Input.GetKeyDown("2")){
spell = spell2;
minusmana = 10;
}

if(Input.GetKeyDown("3")){
spell = spell3;
minusmana = 40;
}

if(Input.GetKeyDown("4")){
if(spell4u == 1);
spell = spell4;
minusmana = 10;
}

if(Input.GetKeyDown("5")){
if(spell5u == 1);
spell = spell5;
minusmana = 10;
}

if(Input.GetKeyDown("6")){
if(spell6u == 1);
spell = spell6;
minusmana = 10;
}

if(Input.GetKeyDown("7")){
if(spell7u == 1);
spell = spell7;
minusmana = 10;
}

if(Input.GetKeyDown("8")){
if(spell8u == 1);
spell = spell8;
minusmana = 10;
}

if(Input.GetKeyDown("9")){
if(spell9u == 1);
spell = spell9;
minusmana = 10;
}

if(Input.GetKeyDown("0")){
if(spell10u == 1);
spell = spell10;
minusmana = 10;
}
}

function OnGUI () {
GUI.color = Color.red;
  GUI.HorizontalScrollbar (Rect (Screen.width * 0.1, Screen.height * 0.87, 180, 15), dummy, health, 0, maxHealth);
  GUI.color = Color.blue;
  GUI.HorizontalScrollbar (Rect (Screen.width * 0.1, Screen.height * 0.9, 180, 15), dummy, mana, 0, maxHealth);
}