function checkform () 
{ 
var form = document.forms[0]
if (form.age.value == "") { 
alert( "please enter your age" ); 
form.age.focus(); 
return false ; 
} 
if (form.retire.value == "") { 
alert( "please enter desired retirement age"); 
form.retire.focus(); 
return false ; 
} 
if (form.retire.value < form.age.value) { 
alert( "retirement age must be larger that current age"); 
form.retire.focus(); 
return false ; 
} 
if (form.income.value == "") { 
alert( "please enter annual income"); 
form.income.focus(); 
return false ; 
} 

if (form.inflation.value == "") { 
alert( "please enter estimeted annual inflation rate"); 
form.inflation.focus(); 
return false ; 
} 
if (form.percent.value == "") { 
alert( "please enter percent of lifestyle to be maintainted"); 
form.percent.focus(); 
return false ; 
} 
if (form.year.value == "") { 
alert( "please enter year in retirement"); 
form.year.focus(); 
return false ; 
} 
if (form.investmentrate.value == "") { 
alert( "please enter annual rate of investment"); 
form.investmentrate.focus(); 
return false ; 
} 
if (form.kwsp.value == "") { 
alert( "please enter KWSP balance upon retirement"); 
form.kwsp.focus(); 
return false ; 
} 
if (form.other.value == "") { 
alert( "please enter ther cash and asset for retirement"); 
form.other.focus(); 
return false ; 
} 
return true ; 
}