Paul's JavaScript Examples | ||
This script will check an entered E-mail address for obvious errors such as a missing @, spaces and other such simple things. Quite useful to help 'newbies' correctly fill in their email address and forego such classics as gte.net!"user@gte.net" that will undoubtedly bounce.
Example
Usage
<INPUT TYPE="TEXT" NAME="Email" VALUE="" SIZE="30" MAXLENGTH="60" onChange="Check_Email(this.value)">
Source
<SCRIPT LANGUAGE="javascript"> <!-- function Check_Email(item) { var returnVal = false checkVal = 0 count1 = 0 count2 = 0 for (var i=0; i < item.length; i++) { if (item.substring(i,i+1) == '@') { checkVal = checkVal + 1 count1 = count1 + 1 } if (item.substring(i,i+1) == '!') { checkVal = checkVal + 2 count2 = count2 + 1 } if (item.substring(i,i+1) == '.') { checkVal = checkVal + 4 } if (item.substring(i,i+1) == ' ') { checkVal = 8 } } if (checkVal == 5 || checkVal == 6) { returnVal = true } else if (checkVal == 0) fout = 'Address not in user@domain.suffix format' if (checkVal == 1) fout = 'Didn\'t find any \'.\' in domain part of e-mail address' if (checkVal == 2) fout = 'Didn\'t find any \'.\' in domain part of e-mail address.' if (checkVal == 3) fout = 'Found both a \'@\' and a \'!\' seperator.\nThat is not allowed!' if (checkVal == 4) fout = 'Didn\'t find a \'@\' or \'!\' seperator.\nThat is not allowed!' if (checkVal == 7) fout = 'Found both a \'@\' and a \'!\' seperator.\nThat is not allowed!' if (checkVal > 7) fout = 'Found space(s) in the E-mail address.\nThat is not allowed!' if (count1 > 1) fout = 'Found multiple instances of \'@\' separator.\nOnly one instance allowed!' if (count2 > 1) fout = 'Found multiple instances of \'!\' separator.\nOnly one instance allowed!' if (returnVal == false) { alert('Your email address seems incorrect.\nSo please doublecheck your input!\n\n \nError Report:\n' + fout) } return returnVal } // --> </SCRIPT>