Why does my onClick() button call the HttpPost method within my controller? - asp.net

Question

I have a button which onClick() execute a JS script, but for some reason it keeps executing my SubmitForm() Action method within my controller and i don't understand why
#using (Html.BeginForm("SubmitForm", "Home", FormMethod.Post,
new
{
traName = Request.Form["nameOfTra"],
amount = Request.Form["amountRequested"],
memberName = Request.Form["commiteeMember"],
date = Request.Form["agmDate"],
signed = Request.Form["signed"],
dated = Request.Form["dated"],
numberOfRows = Request.Form["numberOfRows"]
}))
{
<h1 style="text-align: center;"> TRA grant application </h1>
<h4 style="text-align: center;">This is the TRA Grant form for the association named below who agree to use these funds to cover the cost of administration of the TRA</h4>
<p>
<label for="nameOfTralbl">Name of TRA:</label>
<input type="text" name="nameOfTra" value="" />
</p>
<h4> List of items the money will be spent on</h4>
<table id="traTable">
<tr>
<td>Description of Items</td>
<td>Quantity</td>
<td>Cost</td>
</tr>
<tr>
<td><input type='text' size="30" /></td>
<td><input type='text' size="30" /></td>
<td><input type='text' size="30" /></td>
</tr>
</table>
<br />
<button onclick="addRow()">Add Item</button>
<input type="hidden" id="rows" value="1" name="numberOfRows" />
<script>
function addRow() {
var table = document.getElementById("traTable");
var row = table.insertRow(-1);
var cell1 = row.insertCell(0);
var cell2 = row.insertCell(1);
var cell3 = row.insertCell(2);
cell1.innerHTML = "<input type='text' size='30' id='cell1_" + $('#rows').val() + "'/>";
cell2.innerHTML = "<input type='text' size='30' id='cell2_" + $('#rows').val() + "'/>";
cell3.innerHTML = "<input type='text' size='30' id='cell3_" + $('#rows').val() + "'/>";
$('#rows').val(parseInt($('#rows').val()) + 1)
}
</script>
public ActionResult SubmitForm(string traName, float? amount,
string memberName, string date, string signed, string dated, int? numberOfRows, HttpPostedFileBase file, HttpPostedFileBase file2, HttpPostedFileBase file3){}
I have some extra logic in my Submitform() action which I dont want to execute, I dont understand why it keeps calling this action which it should simply just call the script.

Answer 1

You not declared your submit button to your SubmitForm(). Add inside FormBegin your submit button:
<input type="submit" value="Submit Button" />
#Edit:
Change:
<button onclick="addRow()">Add Item</button>
To:
<input type="button" onclick="addRow()" value="Add Item"/>