[TYPO3] typolink and if.isTrue condition problem.

[Cray Flatline]

I have such construction:
lib.typesmenu = COA
lib.typesmenu.wrap = <ul id="storetypesmenu">|</ul>
lib.typesmenu {
 10 = IMAGE
 10.wrap = <li>|</li>
 10 {
   file = fileadmin/originalwatches/global/img/stroup-male-btn.gif
   stdWrap.typolink.if.isTrue.data = GPvar:tx_commerce_pi1|catUid
   stdWrap.typolink {
    parameter = 59
    additionalParams = &tx_commerce_pi1[gender]=1
    addQueryString = 1
   }
 }

I want to make menu, where where is link on the gif button if
tx_commerce_pi1[catUid] exist in the URL, and just image without link,
if where is no tx_commerce_pi1[catUid].

But with this my construction link displays all the time.

I tried to make
stdWrap.if.isTrue.data = GPvar:tx_commerce_pi1|catUid

but if where is no tx_commerce_pi1[catUid], image doesn't show at all.

Please, help me with it, I have read whole Google to find solution and
didn't find :)

WBR, Cray Flatline