Match regex with numeric value and decimal
<p>I need to match regex to value that is numeric with decimal. Currently I have /^-?[0-9]\d*(.\d+)/ but it does not account for .00 
How would I fix that </p>

<p>Current Valid: </p>

<pre class="lang-none prettyprint-override"><code>1
1.0 
1.33
.00
</code></pre>

<p>Current Invalid: </p>

<pre class="lang-none prettyprint-override"><code>Alpha Character 
</code></pre>