Conditionally assigning value to a variable from a par

How can I conditionally define the value for a variable?

I want to check if the incoming parameter ImageWidth is a non-zero
number. If it is a non-zero numeric string (i.e. it is a non-zero
number) then I want to assign its value to the variable.

If not then I want to assign another parameters value to the variable

Is there a better way to do that checking/ assignment?

Is the following valid??

<xsl:variable name="$ImageWidthRender">
<xsl:choose>
<xsl:when test="$ImageWidth='Nothing'"><xsl:value-of
select="$SBWidth"></xsl:value-of></xsl:when>
</xsl:choose>
<xsl:choose>
<xsl:when test="$ImageWidth='0'"><xsl:value-of
select="$SBWidth"></xsl:value-of></xsl:when>
</xsl:choose>
<xsl:choose>
<xsl:when test="$ImageWidth=''"><xsl:value-of
select="$SBWidth"></xsl:value-of></xsl:when>
</xsl:choose>
<xsl:choose>
<xsl:when test="$ImageWidth=' '"><xsl:value-of
select="$SBWidth"></xsl:value-of></xsl:when>
</xsl:choose>
<xsl:choose>
<xsl:when test="string-length(translate($ImageWidth,'0123456789','')) =
0 and $ImageWidth != 0"><xsl:value-of
select="$ImageWidth"></xsl:value-of></xsl:when>
</xsl:choose>

</xsl:variable>

Abhishek Sanwal
HP - Houston Campus
abhishek.sanwal@xxxxxx

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list