Javascript function not being called from onclick

This has me pulling my hair out. Button on site has onclick=method() and it's not calling the method. The method is supposed to grab all the checkboxes, check their checked state and fill the chk[] array with true/false. The WebMethod then takes that array, breaks it down into three smaller arrays and runs checks on the combinations. So far as I can tell, the button never calls the method to begin with.

aspx page:

<fieldset id="Fieldset">
     <button onclick="SendForm();">Send</button>
     &nbsp;
     <button onclick="CancelForm();">Cancel</button>
</fieldset>
</form>
<asp:ScriptManager ID="ScriptManager1" EnablePageMethods="true" EnablePartialRendering="true" runat="server" />

<script type="text/javascript">
    function SendForm() {
        var email = $get("txtEmail").value;
        var elLength = form1.elements.length;
        var chk = new [42];
        for (i = 0; i < elLength; i++) {
            var count = 0;
            var type = form1.elements[i].type;
            if (type == "checkbox") {
                if (form1.elements[i].checked) {
                    chk[count] = true;
                }
                else {
                    chk[count] = false;
                }
                count++;
            }
            else {
            }
        }
        PageMethods.SendForm(email, chk, OnSucceeded, OnFailed);
    }
</script>

codebehind method it's calling:

[WebMethod]
public static void SendForm(string email, bool[] chk)
{
    bool[] desc = new bool[14];
    bool[] loc = new bool[14];
    bool[] other = new bool[14];
    for (int i = 0; i < 14; i++)
    {
        int count = i * 3;
        desc[i] = chk[count];
        loc[i] = chk[count + 1];
        other[i] = chk[count + 2];

    }
    if (string.IsNullOrEmpty(email))
    {
        throw new Exception("You must supply an email address.");
    }
    else
    {
        if (IsValidEmailAddress(email))
        {
            for (int i = 0; i < 14; i++)
            {
                if (desc[i])
                {
                    if ((loc[i]) && (other[i]))
                    {
                        throw new Exception("Invalid, two parameters selected");
                    }
                    else if (loc[i])
                    {
                        // do stuff
                    }
                    else if (other[i])
                    {
                       // do stuff
                    }
                    else
                    {
                        throw new Exception("Invalid, every exemption must have at least one reason selected");
                    }
                }
                else
                {
                    throw new Exception("No exemptions have been selected");
                }
            }
        }
        else
        {
            throw new Exception("You must supply a valid email address.");
        }
    }
}

EDIT!!: Running the page with the following script instead of the previous script works like a charm. No clue why the previous didn't work.

<script type="text/javascript">
    function SendForm() {
        var email = $get("txtEmail").value;
        var elLength = form1.elements.length;
        for (i=0;i< elLength;i++) {
            var type = form1.elements[i].type;
            if (type == "checkbox" && form1.elements[i].checked) {
                alert("true!");
            }
            else {
                alert("false!");
            }
        }
        PageMethods.SendForm(email, chk, OnSucceeded, OnFailed);
    }
</script>