javascript regex

alphanumericcheck: function(value, min, max ){
var patt = new RegExp('^([a-zA-Z0-9]{'+min+','+max+'})?$');
return patt.test(value);


},
numericcheck: function(value, min, max ){
var patt = new RegExp('^([0-9]{'+min+','+max+'})?$');
return patt.test(value);
},
acquistionIDcheck: function(value, min, max ){
var patt = new RegExp('^([y|n|Y|N]{'+min+','+max+'})?$');
return patt.test(value);
},
emailIDcheck: function(value, min, max ){
var patt = new RegExp('^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$');
return patt.test(value);
}



dateFormatCheck: function(value){
var patt = new RegExp('^([0-9]{2,2}/[0-9]{2,2}/[0-9]{4,4})?$');
var formatvalid= patt.test(value);
if(formatvalid){

   return (new Date(value) !== "Invalid Date" && !isNaN(new Date(value)) )  ? true : false;

}else{
return false;
}
},