I have this to start. I want to take $20 off is someone purchases 2 of productVariantID 113 with the coupon code FBFLASHSALE.

This is working but also takes $20 off if they have only 1 in the cart or any other number. Which bit is wrong?

<xsl:transform version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:template match="/">
<out>
<!--The quantity to qualify for promotion.-->
<xsl:variable name="qualifyQty" select="2" />
<xsl:variable name="productVariantID" select="113" />
<discountAmount>
<!-- Coupon code is always tested in lowercase -->
<xsl:if test="in/salesOrder/couponCodes[couponCode = 'fbflashsale']" >
<xsl:value-of select="-20.00" />
</xsl:if>
</discountAmount>
</out>
</xsl:template>
</xsl:transform>

Hi Marney,

You set the variable but you didn't use it to compare to any data. You're missing the conditions to check bolded in red below. The example below checks if the quantity is greater or equal to your variable, which is 2. If you only want to match exactly 2 items, remove the ">" (this is escaped entity for the ">" symbol to avoid breaking the tags)

<xsl:transform version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<out>
<!--The quantity to qualify for promotion.-->
<xsl:variable name="qualifyQty" select="2" />
<xsl:variable name="productVariantID" select="113" />
<discountAmount>
<!-- Coupon code is always tested in lowercase -->
<xsl:if test="in/salesOrder/couponCodes[couponCode = 'fbflashsale'] and in/this/salesOrderDetail[productVariantID = $productVariantID]/quantity >= $qualifyQty" >
<xsl:value-of select="-20.00" />
</xsl:if>
</discountAmount>
</out>
</xsl:template>
</xsl:transform>

I hope this helps.