[Zope] Searching method using DTML

<dtml-if "_['custname']!=''AND _['custid']==''"> <dtml-call "sqlSearchcust3"> <dtml-elif "_['custid']!=''AND _['custname']==''"> <dtml-call "sqlSearchcust2"> <dtml-elif "_['custid']!=''AND _['custname']!=''"> <dtml-call "sqlSearchcust"> <dtml-else> <dtml-var expr="REQUEST['/Customer/View/searchallcust']"> </dtml-if> The ZOPE error is like :- Expression (Python) Syntax error: invalid syntax , for tag <dtml-if "_['custname']!=''AND _['custid']==''">, on line 20 of a