let's say your have an employee that resigned but after a few month he's coming back
in include/ui/employee_ui.php add function at end
function employee_inactive_row($label, $name, $active=null) {
    echo "<tr><td class='label'>$label</td><td>";
    
    if($active==0){
        echo "<input type='radio' name=$name value='0' checked > Active   ";
        echo "<input type='radio' name=$name value='1'> Resigned    ";
        echo "<input type='radio' name=$name value='2'> Fired";
    }
    elseif($active==1) {
         echo "<input type='radio' name=$name value='0'> Active   ";
        echo "<input type='radio' name=$name value='1' checked> Resigned    ";
        echo "<input type='radio' name=$name value='2'> Fired";
    }
    else {
        echo "<input type='radio' name=$name value='0'> Active   ";
        echo "<input type='radio' name=$name value='1'> Resigned    ";
        echo "<input type='radio' name=$name value='2' checked> Fired";
    }
    echo "</td></tr>";
}
in manage/employee.php
replace line 310 with
employee_inactive_row(_('Status').':', 'EmpInactive', get_post('EmpInactive') );
to handle the fired message replace line 145 with
if (get_post('EmpInactive') == 1 or get_post('EmpInactive') ==2) {
Now your have better options to handle this.
This will solve a database error "Incorrect integer value"