The following list shows the built in functions that can be used in Expressions:

Function	Description
Length(string)	Gets the number of characters in the current string.
Lower(string)	Returns a copy of string converted to lowercase.
Upper(string)	Returns a copy of string converted to uppercase.
Trim(string)	Removes all leading and trailing space from the current string.
Trunc(decimal)	Returns decimal truncated to integer.
IndexOf(string, seek)	Return the zero-based index of the first occurrence of the specified character in this string.
Fill(string, repeatTime)	Return a new string indicated by a specified string repeated a specified number of times.
Matches(string, pattern)	Search the string for first occurrence of specified regular expression
Substring (string, startIndex, length)	Return a substring from current string, which starts at a specified character position and has a specified length. Zero index.
Replace (findString, replaceString, targetString)	Returns a new string in which all occurrences of a specified character in this instance are replaced with another specified character.
StringIIF (statement, option1, option2)	Return option1 if statement is true and option2 otherwise.
DecimalToString(string)	Convert current decimal to its string representation.
IntToString(integer)	Convert current integer to its string representation.
ToInt(string)	Convert the value of current string to an integer.
ToDecimal(string)	Convert the value of current string to a decimal.
ToBool(string)	Convert string to its bool representation.
Today()	Gets current date when the form is in use.
Date(YYYY, MM, DD)	Create a Date to specified year, month and day.
DateIIF(statement, date1, date2)	Return date1 if statement is true and date2 otherwise.
DateDiffDays(date1, date2)	Return the difference between input dates.
AddDays(targetDateTime, days)	Add days to target date and return the result.
AddMonths(targetDateTime, months)	Add months to target date and return the result.
AddYears(targetDateTime, years)	Add years to target date and return the result.
AddHours(targetDateTime, hours)	Add hours to target date and return the result.
DateTime(YYYY, MM, DD, hh, mm, ss	Create a Date to specified year, month, day, hour, minute and second.
GetChoiceId(fieldName, optionText)	Get the id of specified choice list value name for a case field.
GetChoiceValue(fieldName, id)	Get the display text of specified choice id for a case field.
Sum(mvalFieldAsString, condition)	Return the sum of mvalfield (repeating field) in selected rows filtered by condition expression. If condition is blank string, no filter applied.
Min(mvalFieldAsString, condition)	Return the minimum value of repeating field from selected rows filtered by condition expression.
Max(mvalFieldAsString, condition)	Return the maximum value of repeating field from selected rows filtered by condition expression.
Count(groupName, condition)	Return the count of selected rows filtered by condition expression in a repeating group.
Avg(mvalFieldAsString, condition)	Return the average value of repeating field of selected rows filtered by condition expression.
Ceil(decimal)	Rounds up a number to nearest integer.
Floor(decimal)	Rounds down a number to nearest integer.
DateToString(datetime, format)	Converts datetime to the specified string format.
DecimalRound(decimal, digitsafterdecimal)	Rounds a decimal to specific digits after decimal.
GetQueryStringValue(key)	Get query string value by key.
GetSessionValue(key)	Get session value by key.
Join(mvalFieldAsString, separator, condition)	Join values from repeating fields of a group based on condition using a separator.
Not(expression)	Returns true if a boolean value of expression is false or null. Returns false if the boolean value is true or not null.
NewGuid()	Returns a new global Unique ID.
Now()	Returns the current system date and time.
Round(decimal)	Rounds a number to the nearest integer.
UserName()	Returns the current user name.
SetSessionValue(key, value)	Set session value to a key.
SubstringBefore(target, searchString)	Returns the text in the first text string that precedes the first occurrence of the second text string.
SubstringAfter(target, searchString)	Returns the text in the first text string that follows the first occurrence of the second text string.
Translate(target, searchCharacters, replaceCharacters)	Returns the first text string with each character in the second text string replaced by the character at the corresponding position in the third text string.

Indexer Fields