presave function not working for multiple fields

Question

var j = jQuery.noConflict();

function PreSaveAction() { 
    var txtTitle = $("#ctl00_ctl41_g_648c8386_16ca_4729_9c59_c9757150bafe_ff21_ctl00_ctl00_TextField").val();    //Application Name
    //alert(txtTitle);
    if (txtTitle == '') {        
        alert("Value Cannot be Blank in Application Name");          
        return false;
    } else {
        return true;
    } 


    var txtTitle1 = $.("#ctl00_ctl41_g_648c8386_16ca_4729_9c59_c9757150bafe_ff31_ctl00_ctl00_TextField_inplacerte").val();    //Description
    if (txtTitle1 == '') {        
        alert("Value Cannot be Blank in Description");          
        return false;
    } else {
        return true;
    }    
}

Answer 1

You have two problems:

1. Your txtTitle1 variable is equal to $.(. Just remove that dot after the dollar sign.
2. Your Description field seems to contain rich HTML because the field ID in the DOM contains the word _inplacerte at the end, therefore the value() jQuery function will not work since the field is not an input or textarea element, but rather a DIV element. In this case you need to replace value() with text().trim().

Also, here a version of your code without jQuery. The $get function is a shortcut for Sys.UI.DomElement.getElementById and it is available everywhere on SharePoint as it is part of the ASP.NET Ajax library. There is no point in using jQuery, unless you use it for some other things on the page.

function PreSaveAction() { 
    var applicationNameField = $get("ctl00_ctl41_g_648c8386_16ca_4729_9c59_c9757150bafe_ff21_ctl00_ctl00_TextField");
    var descriptionField = $get("ctl00_ctl41_g_648c8386_16ca_4729_9c59_c9757150bafe_ff31_ctl00_ctl00_TextField_inplacerte");

    if (applicationNameField && applicationNameField.value.trim() === "") {        
        alert("Value Cannot be Blank in Application Name");          
        return false;
    }

    if (descriptionField && descriptionField.textContent.trim().length < 2) {        
        alert("Value Cannot be Blank in Description");          
        return false;
    }

    return true;
}

Answer 2

I suggest you to use this code $("input[title='your field name']").val() to get text value for best practice. Because text field ID is dynamically generated id in SHAREPOINT and return true at end of the method

your code should be

var j = jQuery.noConflict();
        function PreSaveAction() { 
        var txtTitle = $("input[title='your Application ield name']").val() ;    //Application Name

        var txtTitle1 = $("input[title='your descriptiom field name']").val() ; 

           //alert(txtTitle);
           if(txtTitle == '' && txtTitle1 == '')
      {        
           alert("Value Cannot be Blank in Application Name");          
           return false;
        }
        else{
           return true;
            }   

        }

Answer 3

Since the field is a Rich text multi-line field, if you look into the DOM (using Firebug or IE tool) there would be some values in it. like empty < p> tags.

Try the following:

function stripHtml(body) {
  var regex = /(<([^>]+)>)/ig;
  var result = body.replace(regex, "");
  return result;
}

var textFieldHtml = $("div[id='ctl00_ctl41_g_648c8386_16ca_4729_9c59_c9757150bafe_ff31_ctl00_ctl00_TextField_inplacerte']");
var textFieldHtmlBody = textFieldHtml.html();
window.console && console.log(textFieldHtmlBody);

var textFieldValue = $.trim(stripHtml(textFieldHtmlBody));
if(textFieldValue) {
   window.console && console.log(textFieldValue);
   //return false; 
}
else
   window.console && console.log('Null or undefined');