I'm trying to create a form in SharePoint Designer 2013, I want to be able to hide a specific field in the form unless the answer to another field has been changed to a specific option. Here is my code:
<tr>
<td width="25%" class="ms-vb">
<b>External Sales?:</b>
</td>
<td width="75%" class="ms-vb">
<SharePoint:FormField runat="server" id="ff438747{$Pos}" ControlMode="New" FieldName="External_x0020_Sales_x003f_" __designer:bind="{ddwrt:DataBind('i',concat('ff438747',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@External_x0020_Sales_x003f_')}" />
<SharePoint:FieldDescription runat="server" id="ff219374description219373{$Pos}" FieldName="External_x0020_Sales_x003f_" ControlMode="Edit" />
</td>
</tr>
<xsl:if test="@External_x0020_Sales_x003f_ = 'Yes'">
<tr>
<td width="25%" class="ms-vb">
<b>PPE:</b>
</td>
<td width="75%" class="ms-vb">
<SharePoint:FormField runat="server" id="ff438748{$Pos}" ControlMode="New" FieldName="PPE" __designer:bind="{ddwrt:DataBind('i',concat('ff438748',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@PPE')}" />
<SharePoint:FieldDescription runat="server" id="ff219375description219373{$Pos}" FieldName="PPE" ControlMode="Edit" />
</td>
</tr>
</xsl:if>
As you can see, I want to be able to make it so when "External Sales?" = Yes, then it shows the field "PPE".
Any help on this matter would be greatly appreciated.