// Write a JavaScript function that checks whether a passed string is palindrome or not?   
  
function check_Palindrome(str_entry){  
// Change the string into lower case and remove  all non-alphanumeric characters  
   var cstr = str_entry.toLowerCase().replace(/[^a-zA-Z0-9]+/g,'');  
    var ccount = 0;  
// Check whether the string is empty or not  
    if(cstr==="") {  
        alert("Nothing found!");  
        return false;  
    }  
// Check if the length of the string is even or odd   
    if ((cstr.length) % 2 === 0) {  
        ccount = (cstr.length) / 2;  
    } else {  
// If the length of the string is 1 then it becomes a palindrome  
        if (cstr.length === 1) {  
            alert("Entry is a palindrome.");  
            return true;  
        } else {  
// If the length of the string is odd ignore middle character  
            ccount = (cstr.length - 1) / 2;  
        }  
    }  
// Loop through to check the first character to the last character and then move next  
    for (var x = 0; x < ccount; x++) {  
// Compare characters and drop them if they do not match   
        if (cstr[x] != cstr.slice(-1-x)[0]) {  
            alert("Entry is not a palindrome.");  
            return false;  
        }  
    }  
    alert("The entry is a palindrome.");  
    return true;  
}  
check_Palindrome('madam');  
check_Palindrome('nurses run');  
check_Palindrome('fox');  