<?php 

function haveCommonWord($string1, $string2) {
// Split the strings into arrays of words
$words1 = explode(" ", $string1);
$words2 = explode(" ", $string2);

// Convert all words to lowercase for case-insensitive comparison
$words1 = array_map('strtolower', $words1);
$words2 = array_map('strtolower', $words2);

// Check for intersection of the two arrays
$commonWords = array_intersect($words1, $words2);

// Return true if there is at least one common word, false otherwise
return !empty($commonWords);
}

// Example usage
$string1 = "Dehradun, Uttarakhand, India";
$string2 = "Airport, Jolly grant,";
if (haveCommonWord($string1, $string2)) {
echo "The strings have at least one common word.";
} else {
echo "The strings do not have any common words.";
}

?>