I have the folowing xml code:

```
<weather-code>14 3</weather-code>
<weather-code>12</weather-code>
<weather-code>7 3 78</weather-code>

```

Now i'd like to only grab the first number of each node to set a background image. So for each node i have the folowing xslt:

```
<xsl:attribute name="style">
  background-image:url('../icon_<xsl:value-of select="substring-before(weather-code, ' ')" />.png');
</xsl:attribute>

```

Problem is that substring before doesn't return anything when there's no space. Any easy way around this?