If value in select option is lower than in second select option, then change option

I want to achieve:

If I select "16" in first select box and bigger value in second, for example "17", then in second select automatically changing to "16".

Just if value in first select box is lower than second, always change to same values, for example 16 to 16, 18 to 18.

<select id="from_age_js" name="from_age" class="select-advertise-style">
   <option value="f13">13</option>
   <option value="f14">14</option>
   <option value="f15">15</option>
   <option value="f16">16</option>
   <option value="f17">17</option>
   <option value="f18" selected>18</option>
   <option value="f19">19</option>
   <option value="f20">20</option>
</select>
—
<select id="to_age_js" name="to_age" class="select-advertise-style">
   <option value="t13">13</option>
   <option value="t14">14</option>
   <option value="t15">15</option>
   <option value="t16">16</option>
   <option value="t17">17</option>
   <option value="t18">18</option>
   <option value="t20" selected>20+</option>
</select>