<select name="category">
<option value="0">Select Category</option>
<option value="1">ABC</option>
<option value="2">123</option>
<option value="3">abc</option>
</select>
if i select ABC category then show only this category subcategories:-
<select name="subcategory">
<option value="0">Select Sub-Category</option>
<option value="1">A</option>
<option value="2">B</option>
<option value="3">C</option>
</select>
if i select 123 category then show only this category subcategories:-
<select name="subcategory">
<option value="0">Select Sub-Category</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
if i select abc category then show only this category subcategories:-
<select name="subcategory">
<option value="0">Select Sub-Category</option>
<option value="1">a</option>
<option value="2">b</option>
<option value="3">c</option>
</select>
if select category then show subcategories of this selected category
how make javascript for this please help me thank you.