After searching the web, I found a site that will make
css based buttons online. I noticed they used the style attribute/property.
I incorporated that into my <input type="button"...> tag and the javascript was executed and the <form action="vndrAddReg3.
php" was not executed.
Problem solved.
Here are the working buttons:
<input type='button' value='-' class='delrow' id='delrow' style='text-align:center; background:#E7F0F5; border:#CDD7DC 2px solid; padding:1px; color:#000000; font-family:tahoma; font-size:10px; font-weight:900; height:20px;width:20px;'/>
<input type='button' value='+' class='addrow' id='addrow' style='text-align:center; background:#E7F0F5; border:#CDD7DC 2px solid; padding:1px; font-family:tahoma; font-size:13px; font-weight:900; height:20px; width:20px;'/>