how to use if else in alert activity

hi all,

I am reading the value of variable 

vars.value1 in alert activity

this vars.value1 is coming from Javascript activity placed before alert activity

like javascripti actiovty==>Alert activity

this value <%=vars.value1%> has some values whuch its displaying in alert activity as output when 

we receieve alert email..

my ask is if value of vars.value1  is coming as 0 

from javascript activity

then I would  like to do if else statement 

if vars.value1=0

then print no records found

need help here how can i add if else in alert activity

please help

need help with syntax

if vars.value1 is greater than 0 than print

<%=vars.value1%>

(this case i am able to achieve)

@_manoj_kumar_ 
@parthasarathy 

@akshayanand