javascript表单计算器 - 从下拉列表中设置值

Question

我有一个具有执行计算功能的表单，虽然它没有在控制台中抛出任何错误但我无法正常工作。当我选中复选框时，它不会保持检查状态。当我从下拉菜单中选择省份时，基本上应该设置适当的政府费用，我们的费用和税额。

//my array
var price_govStatus = new Array(14)
    price_govStatus[0] = 17.50 //Alberta
    price_govStatus[1] = 26.68 //British Columbia
    price_govStatus[2] = 35 //Manitoba
    price_govStatus[3] = 20  //New Brunswick
    price_govStatus[4] = 10  //Newfoundland
    price_govStatus[5] = 10 //Northwest Territories
    price_govStatus[6] = 37.40  //Nova Scotia
    price_govStatus[7] = 10  //Nunavut
    price_govStatus[8] = 26.00 //Ontario
    price_govStatus[9] = 30 //Prince Edward Island
    price_govStatus[10] = 34.34 //Quebec
    price_govStatus[11] = 20  //Saskatchewan
    price_govStatus[12] = 15 //Yukon
    price_govStatus[13] = 10 //Canada 

function checkJurisdictions() {

if ((theForm.Corporate_Profile_Report.checked == true) && (theForm.corpsearchprov.selectedIndex >= 0) )
                    {
                        dis_govfee_corporate_profile_report = price_govCorpProfile[theForm.corpsearchprov.selectedIndex];
                        theForm.dis_govfee_corporate_profile_report.value = formatCurrency(price_govCorpProfile[theForm.corpsearchprov.selectedIndex]);
                    }

                    else
                    {
                        dis_govfee_corporate_profile_report = 0;
                        theForm.dis_govfee_corporate_profile_report.value = formatCurrency('0.00');
                    }

if ((theForm.Certificate_Status.checked == true) && (theForm.statusprov.selectedIndex != 6))
                    {
                        dis_govfee_certstatus = price_govStatus[theForm.statusprov.selectedIndex];
                        theForm.dis_govfee_certstatus.value = formatCurrency(price_govStatus[theForm.statusprov.selectedIndex]);

                        dis_ourfee_certstatus = 30;
                        theForm.dis_ourfee_certstatus.value = formatCurrency('30.00');
                        dis_tax_certstatus = 3.90;                  
                    }

                    else if ((theForm.Certificate_Status.checked == true) && (theForm.statusprov.selectedIndex = 6))
                    {
                        dis_govfee_certstatus = 37.40;
                        theForm.dis_govfee_certstatus.value = formatCurrency('37.40');
                        dis_ourfee_certstatus = 35;
                         theForm.dis_ourfee_certstatus.value = formatCurrency('35.00');
                         dis_tax_certstatus = 4.55;
                    }

                    else if (theForm.Certificate_Status.checked == false) 
                    {
                        dis_govfee_certstatus = 0;
                        theForm.dis_govfee_certstatus.value = formatCurrency('0.00');
                        dis_ourfee_certstatus = 0;
                         theForm.dis_ourfee_certstatus.value = formatCurrency('0.00');
                         dis_tax_certstatus = 0;
                    }

}

我的HTML

<select  onChange="Form_Calculator();" id="statusprov" name="statusprov">
<option value="Alberta">Alberta</option>
<option value="British Columbia">British Columbia</option>
<option value="Manitoba">Manitoba</option>
<option value="New Brunswick">New Brunswick</option>
<option value="Newfoundland">Newfoundland</option>
<option value="Northwest Territories">Northwest Territories</option>
<option value="Nova Scotia">Nova Scotia</option>
<option value="Nunavut">Nunavut</option>
<option value="Ontario">Ontario</option>
<option value="Prince Edward Island">Prince Edward Island</option>
<option value="Quebec">Quebec</option>
<option value="Saskatchewan">Saskatchewan</option>
<option value="Yukon">Yukon</option>    
<option value="Canada">Canada</option>
</select>