Ultimate Skill Easy Custom Damage Formula

[Arekushisu]

Someone can tell me what did i do wrong ?

variables :
var hittype = 0; (If 0 : 'atk', 'def' and 'pdr' based damages ; else: 'mat', 'mdf' and 'mdr' based dmg)

var mindmg = 10; (base damage for the skill)
var maxdmg = 20; (damage range)
var docri = 6; (critical base damage bonus)


var minheal = 0; (base heal ammount)
var maxheal = 0; (heal range ammount)
car criheal = 0; (critical heal ammount)

var paminus = 3; (How many Mana Points will be removed by the skill to the enemy)

Skill TAG :

<damage formula>

var hittype = 0;

var mindmg = 10;
var maxdmg = 20;
var docri = 6;

var minheal = 0;
var maxheal = 0;
car criheal = 0;

var paminus = 3;

if (target.isActor() === user.isActor()) {
value = minheal + Math.random(maxheal-minheal+1);
if (target.result().critical) {
value = criheal;
}
value *= 1 + a.mat/100;
value += a.pha;
if (value < 0) {
value = 0;
}
value = -1 * Math.abs(value);
} else {
value = mindmg + Math.random(maxdmg-mindmg+1);
if (target.result().critical) {
value += docri;
}
if (hittype = 0) {
value *= 1 + a.atk/100;
value += a.def - b.pdr;
} else {
value *= 1 + a.mat/100;
value += a.mdf - b.mdr;
}
if (target.result().critical) {
value += a.cnt - b.cev;
}
if (value < 0) {
value = 0;
}
}

if (paminus > 0) {
var malus = 0;
var ret = a.mev;
var esc = b.mrf;
var items = [];
for (var i = 1; i <= paminus; i++) {
var tenta = 50*(ret/esc)*(b.mp/b.mmp);
tenta = Math.max(10, Math.min(90, tenta));
var rndm = Math.randomInt(100)+1;
if(rndm < tenta) {
malus += 1;
}
items.push(i);
}
b.gainMp(-malus);
}

</damage formula>