Regarding New-Page using SAPSCRIPT-COUNTER_X

I Used SAPSCRIPT-COUNTER_X parameter in a main window. I have initialized it to 1 by using DEFINE statement. Next i put condition &SAPSCRIPT-COUNTER_X& = '13' in IF statement . if it is 13 then it counter NEW-PAGE control command. But it is not working fine. Can any one suggest me how to work with SAPSCRIPT-COUNTER_X? Urgent in my project....