Date/Time field format not wysiwyg

Question

I have a date field in my form that I formatted as m/d/yyyy hh:mm.  I thought that because it formats that field in that way my script would get passed down that way however it is not.  I want to manipulate it so the value is in the format I want it to be....
I enter this in the date/time field: April 1, 2011 1:40PM
When I click out of the field and I see: 4/1/2011 13:40
Then I have a script that uses this field to make the file name but because I have a comma in there it will not save, if I take the comma out it will save.  So the main question is how do I format my field to pass down the value that I am seeing not the value that I am typing in.  You will notice I have a replace in there but I can't account for the comma because it reads it as part of the syntax.
// Get the field value
var dtentered = getField("datetime").value;  
//replace any odd characters that will not allow the file to save
var fdt = dtentered.replace(/[!@#$%^&*()+=|\:;"'<>?/{}]/g,"_");  
// Specify the folder
var fldr = "/c/WO Completed/";
// Determine the full name and path
var fp = fldr +  fdt + ".pdf";

Answer 1

Thanks for the response...I'm not sure that I understand what you mean back-slash...I went ahead and did this but now it is giving me an odd file name
// Get the field value
var dt = getField("datetime").value;
var mydt = escape(dt);
//replace any odd characters that will not allow the file to save
var fdt = mydt.replace(/[!@#$%^&*()+=|\:;"'<>?/{}]/g,"_");
// Specify the folder
var fldr = "/c/WO Completed/";
// Determine the full name and path
var fp = fldr + fdt + ".pdf";
Returns a file name as
April_201_2C_202011_201_3A40PM.pdf
I was looking more for
4_1_2011_13_40.pdf
or
April_1_2011_1_40PM.pdf