I can't seem to find the error in this script. The error is "Object doesn't support this property or method" and is most likely in the "average" function:

<script>
function getit() {
var attack = document.former.attack.value;
var defense = document.former.defense.value;
var strength = document.former.strength.value;
var hits = document.former.hits.value;
var magic = document.former.magic.value;
var ranged = document.former.ranged.value;
var prayer = document.former.prayer.value;

var cooking = document.former.cooking.value;
var woodcutting = document.former.woodcutting.value;
var fletching = document.former.fletching.value;
var fishing = document.former.fishing.value;
var firemaking = document.former.firemaking.value;
var crafting = document.former.crafting.value;
var smithing = document.former.smithing.value;
var mining = document.former.mining.value;
var herblaw = document.former.herblaw.value;
var quest = document.former.quest.value;

if (attack == "" || defense == "" || strength == "" || hits == "" || magic == "" || prayer == ""){alert("You must fill ALL of the required text boxes!")}
else{
document.former.result.value=(((parseInt(attack) + parseInt(strength) + parseInt(defense) + parseInt(hits)) / 4) + (parseInt(magic) + parseInt(prayer)) / 8)

}
}
function allstats() {
var attack = document.former.attack.value;
var defense = document.former.defense.value;
var strength = document.former.strength.value;
var hits = document.former.hits.value;
var magic = document.former.magic.value;
var ranged = document.former.ranged.value;
var prayer = document.former.prayer.value;

var cooking = document.former.cooking.value;
var woodcutting = document.former.woodcutting.value;
var fletching = document.former.fletching.value;
var fishing = document.former.fishing.value;
var firemaking = document.former.firemaking.value;
var crafting = document.former.crafting.value;
var smithing = document.former.smithing.value;
var mining = document.former.mining.value;
var herblaw = document.former.herblaw.value;
var quest = document.former.quest.value;
if (attack == "" || defense == "" || strength == "" || hits == "" || magic == "" || ranged == "" || prayer == "" || cooking == "" || woodcutting == "" || fletching == "" || fishing == "" || firemaking == "" || crafting == "" || smithing == "" || mining == "" || herblaw == "" || quest == "") {alert("You must fill ALL of the text boxes!")}
else{
document.former.total.value=parseInt(attack) + parseInt(defense) + parseInt(strength) + parseInt(hits) + parseInt(magic) + parseInt(ranged) + parseInt(prayer) + parseInt(cooking) + parseInt(woodcutting) + parseInt(fletching) + parseInt(fishing) + parseInt(firemaking) + parseInt(crafting) + parseInt(smithing) + parseInt(mining) + parseInt(herblaw) + parseInt(quest)
}
}

function average() {
var attack = document.former.attack.value;
var defense = document.former.defense.value;
var strength = document.former.strength.value;
var hits = document.former.hits.value;
var magic = document.former.magic.value;
var ranged = document.former.ranged.value;
var prayer = document.former.prayer.value;

var cooking = document.former.cooking.value;
var woodcutting = document.former.woodcutting.value;
var fletching = document.former.fletching.value;
var fishing = document.former.fishing.value;
var firemaking = document.former.firemaking.value;
var crafting = document.former.crafting.value;
var smithing = document.former.smithing.value;
var mining = document.former.mining.value;
var herblaw = document.former.herblaw.value;
var quest = document.former.quest.value;
if (attack == "" || defense == "" || strength == "" || hits == "" || magic == "" || ranged == "" || prayer == "" || cooking == "" || woodcutting == "" || fletching == "" || fishing == "" || firemaking == "" || crafting == "" || smithing == "" || mining == "" || herblaw == "" || quest == "") {alert("You must fill ALL of the text boxes!")}
else {
document.former.average.value=((parseInt(attack) + parseInt(defense) + parseInt(strength) + parseInt(hits) + parseInt(magic) + parseInt(ranged) + parseInt(prayer) + parseInt(cooking) + parseInt(woodcutting) + parseInt(fletching) + parseInt(fishing) + parseInt(firemaking) + parseInt(crafting) + parseInt(smithing) + parseInt(mining) + parseInt(herblaw) + parseInt(quest)) / 17)
}

}

</script>

<form name="former">
Attack: <input type="text" name="attack">
<p>Strength: <input type="text" name="strength">
</p>
<p>Defense: <input type="text" name="defense">
</p>
<p>Hits: <input type="text" name="hits">
</p>
<p>Ranged: <input type="text" name="ranged">
</p>
<p>Prayer: <input type="text" name="prayer">
</p>
<p>Magic: <input type="text" name="magic">
</p>
<p>&nbsp;
</p>
<p>Cooking: <input type="text" name="cooking">
</p>
<p>Woodcutting: <input type="text" name="woodcutting">
</p>
<p>Fletching: <input type="text" name="fletching">
</p>
<p>Fishing: <input type="text" name="fishing">
</p>
<p>Firemaking: <input type="text" name="firemaking">
</p>
<p>Crafting: <input type="text" name="crafting">
</p>
<p>Smithing: <input type="text" name="smithing">
</p>
<p>Mining: <input type="text" name="mining">
</p>
<p>Herblaw: <input type="text" name="herblaw">
</p>
<p>Quest Points: <input type="text" name="quest">
</p>


<p>&nbsp;&nbsp;</p>


<p> Fighting Stats: <input type="text" name="result">&nbsp; </p>
<p>&nbsp;&nbsp;
<p> Total Points: <input type="text" name="total"> </p>


&nbsp;
<p>Average: <input type="text" name="average">
<br>


</p>
<p>


<input type="button" name="sub" onClick="getit()" value="Calculate PK Level">
<input type="button" name="sub2" onClick="allstats()" value="Calculate ALL Stats">
<input type="button" name="sub3" onClick="average()" value="Calculate Average">

</form>
</p>