[xsl] Locating an attribute and its value indirectly

["Mark" <mark@xxxxxxxxxxxx>]

I do not know how to write the following code to get the value of an 
attribute named in the current element but found in another element:

In this case, where @text-location is 'souvenir-sheet', I want the value 
'2630'.

when the context is <Inscriptions>
<Thing>
   <Inscriptions czech="XIV. Zimnm olympijski hry Sarajevo '84" eng="14th 
Winter Olympic Games, Sarajevo, '84" text-location="souvenir-sheet"/>
   <Formats souvenir-sheet="2630"/>
</Thing>

<xsl:value-of select="../Formats/@*=@text-location"/>
returns a boolean and

<xsl:value-of select="../Formats/@*[name(.)=@text-location]"/>
returns a blank

Am I even close? What am I doing wrong?

Thanks,
Mark