form validation

[nareshsourav]

hi
can any one provide me the form validation.There is a field phone no and email address which user has to enter.so any one can help me in providing the validations for this two fields.The user has to enter the numbers for the phone nunber and it should no accept the char.

[Malith]

function checkemail(){
var str=document.validation.emailcheck.value
var filter=/^.+@.+\..{2,3}$/

if (filter.test(str))
testresults=true
else {
alert("Please input a valid email address!")
testresults=false
}
return (testresults)
}

[Malith]

var emailFilter=/^.+@.+\..{2,3}$/;
if (!(emailFilter.test(strng))) {
error = "Please enter a valid email address.\n";
}

[Malith]

function isNumeric(strString)
{
var strValidChars = "0123456789";
var strChar;
var isOk = true;

if (0 == strString.length)
{
isOk = false;
}

// Test strString consists of valid characters listed above
for (i = 0; (i < strString.length) && isOk; i++)
{
strChar = strString.charAt(i);
if (-1 == strValidChars.indexOf(strChar))
{
isOk = false;
}
}

return isOk;
}