Thanks to Leigh and your excellent help! The checkbox tip was the fix (name="userIDList" value="#ID#")
Here is the final working Insert.cfm (some html stripped out)
<!--- Create the Manager Monthly Accruals (Mgt) dataset --->
<cfquery name="rsLeaveTimeManagerAccruals" datasource="care">
SELECT tblusers.ID, username as ltUser, status, active, email, hiredate, tblUsers.picture AS eP
, TIMESTAMPDIFF(YEAR, hiredate, NOW()) AS year_passed
, TIMESTAMPDIFF(MONTH, hiredate, NOW()) MOD 12 AS month_passed
, TIMESTAMPDIFF(DAY, hiredate, NOW()) MOD 365 AS day_passed
, CONCAT(TIMESTAMPDIFF(YEAR, hiredate, NOW())," years, ",TIMESTAMPDIFF(MONTH, hiredate, NOW()) MOD 12," months, ",TIMESTAMPDIFF(DAY, hiredate, NOW()) MOD 365," days") AS EmployLengthActive
, TIMESTAMPDIFF(YEAR, hiredate, NOW()) AS monthly_accrual_time
, CASE WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) < 1
THEN '0'
WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) <= 5
THEN '14'
WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) >= 6
THEN '18'
END AS ltHours
FROM v_reports_to_mgt_list LEFT OUTER JOIN tblusers ON tblusers.ID = v_reports_to_mgt_list.id
WHERE clr_accrual = '1' AND hiredate IS NOT NULL
ORDER BY hiredate
</cfquery>
<!-- Add a checkbox to Select / Deselect All -->
<script type="text/javascript">
checked=false;
function checkedAll (frm1) {
var aa= document.getElementById('form1');
if (checked == false)
{
checked = true
}
else
{
checked = false
}
for (var i =0; i < aa.elements.length; i++)
{
aa.elements[i].checked = checked;
}
}
</script>
<!-- Script by hscripts.com -->
.....html....
<form action="leave_time_manager_accruals_insert.cfm" method="post" id="form1">
<table border="1" cellpadding="1" cellspacing="1">
<tr>
<td><input type='checkbox' name='checkall' onclick='checkedAll(form1);'> Check All?</td>
<td>Username</td>
<td>Status</td>
<td>Active</td>
<td>Hiredate</td>
<td>Employee Length</td>
<td>Management_Accrual</td>
</tr>
<cfoutput query="rsLeaveTimeManagerAccruals">
<tr class="#iif(currentrow MOD 2,DE('lightrow'),DE('darkrow'))#">
<td><img src="../images/employees/#eP#" alt="" width="24" height="28" title=""/>
<input type="checkbox" name="userIDList" value="#ID#" title="Check this box and click Submit button to add Leave Time Accruals to database." /></td>
<td>#rsLeaveTimeManagerAccruals.ltUser#</td>
<td>#rsLeaveTimeManagerAccruals.status#</td>
<td>#rsLeaveTimeManagerAccruals.active#</td>
<td>#rsLeaveTimeManagerAccruals.hiredate#</td>
<td>#rsLeaveTimeManagerAccruals.EmployLengthActive#</td>
<td><div align="center">#rsLeaveTimeManagerAccruals.ltHours#</div></td>
</tr>
</cfoutput>
<td><input type="submit" name="Submit" id="Submit" value="Submit" title="Clicking this button will add all checked Managers Leave Time Accruals to database."/></td>
</table></form>
Here is the final working Action.cfm (some html stripped out)
<cfparam name="form.ltUser" default="">
<cfparam name="form.ltHours" default="">
<cfparam name="form.userIDList" default="1">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Leave Time Added</title>
</head>
<body>
<cfquery name="rsInsertLeaveTimeManagerAccruals" datasource="care">
INSERT INTO tblLeaveTime ( ltUser, ltHours, ltCreated, ltType, ltCreatedBy)
SELECT v_reports_to_mgt_list.reports_to,
CASE WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) < 1
THEN '0'
WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) <= 5
THEN '14'
WHEN FLOOR(DATEDIFF(NOW(), hiredate) / 365) >= 6
THEN '18'
END AS ltHours, NOW(), "Accrual", "cf_admin"
FROM v_reports_to_mgt_list LEFT OUTER JOIN tblusers ON tblusers.ID = v_reports_to_mgt_list.id
WHERE v_reports_to_mgt_list.ID IN
(
<cfqueryparam value="#FORM.userIDList#" cfsqltype="cf_sql_integer" list="true">
)
</cfquery>
<h1>Management Leave Time successfully added to database! </h1>
Click <a href="leave_time_mgt_l01.cfm">here</a> to return to Admin page
</body>
</html>