string functions



& concatenation

sleft		substring from start of string
sright		substring from end of string
smid		substring from the middle of the string

insert		insert substring at position i
sdelete		delete chars at position i

ssearch		search for substring

srepch		produce a repeated string of characters, e.g. '00000', '....'

asc/chr		return numberic code/convert to text item


ucase		convert to uppercase
lcase		convert to lowercase