Nested if condition in kendo grid column template

While trying to implement condition function in kendo grid column template, there is a problem happening, data from my grid are not shown, my function is

function material() {
  if (PCommonPortalMethods.GetSiteLanguage() == 'en') {
    if (data.Unit._Key) {
      Unit.UnitGlobalName
    }
    else ('')
  }
  else {
    if (data.Unit._Key) {
      Unit.UnitLocalName
    }
    else ('')
  }
}      

and I call it from template like : template:'#= material() #'

I tried something like that also:

template: "#if (PCommonPortalMethods.GetSiteLanguage() == 'en') {# if(data.Unit._Key) #=Unit.UnitGlobalName#  else(" ") #} else { # if(data.Unit._Key) #=Unit.UnitLocalName#  else(" ") #} #"

can someone help me? what am I doing wrong? Thanks