function valida(){

///////////YEAR FIELD///////////////
if(document.findy.findy.value==""){
alert("Please enter year");
document.findy.findy.focus();
return false;
}
if (isNaN(document.findy.findy.value))
{
alert("Year should be a number");
document.findy.findy.focus();
document.findy.findy.value="";
return false;
}

var abc = document.findy.findy.value;
if (abc.length!=4)
{
alert("Year should be a 4 digit number. Please enter the correct year");
document.findy.findy.focus();
document.findy.findy.value="";
return false;	
}

var minYear=1900;
var maxYear=2100;
if(abc<minYear || abc>maxYear)
{
alert("Please enter year between "+minYear+" and "+maxYear);
document.findy.findy.focus();
document.findy.findy.value="";
return false;		
}
///////////////////////////
}